Analog circuit voltage switching circuit

Abstract

The utility model relates to a voltage switching circuit of an analog circuit. The voltage switching circuit comprises a step-down switching circuit composed of a TMI3343B and a step-up switching circuit composed of an AH6910. The device supports a low power consumption mode and a high power consumption mode, the obtained audio can meet different requirements of users, control modes can be diversified, real-time switching of voltage boosting and voltage reducing of an analog circuit is achieved, meanwhile, the production cost is reduced, half of the cost can be saved, and the price advantage is obvious.

Description

TECHNICAL FIELD

[0001] The patent application belongs to the technical field of analog circuit voltage switching, and more particularly to an analog circuit voltage switching circuit. BACKGROUND

[0002] More and more products in electronic audio circuits need to support low-power and high-power modes, such as supporting only low power in USB power supply mode, and supporting high-power mode when a DC power socket is inserted, which can make the audio input or output have greater signals and dynamics, and the sound heard is more delicate, and the audio with lower distortion and greater dynamics can be obtained. Therefore, a real-time analog circuit voltage boost and buck switching circuit needs to be designed, so that the control mode can be diversified, such as supporting encoder control, button control or upper computer control. CONTENT OF THE UTILITY MODEL

[0003] The technical problem to be solved by the utility model is to provide an analog circuit voltage switching circuit which supports low-power and high-power modes, can meet different needs of users, and can diversify the control mode.

[0004] To solve the above problems, the technical scheme adopted by the utility model is:

[0005] An analog circuit voltage switching circuit comprises a buck switching circuit, a boost switching circuit,

[0006] The buck switching circuit comprises a buck converter U13, a capacitor C67 connected between the BOOT pin of U13 and the SW switch pin, the SW switch pin of U13 connected with an inductor L7, the other end of the inductor L7 connected with GND; the GND pin and the PGND pin of U13 connected with GND through a diode D3; the COMP pin of U13 connected with a capacitor C77 and a resistor R148 in sequence and then connected with the diode D3; the EN pin of U13 connected with a resistor R143, the other end of the resistor R143 connected with the VIN pin of U13; the VIN pin of U13 further connected with a capacitor C76, a capacitor C75, a capacitor C74 and a resistor R141, the other end of the capacitor C76 and the other end of the capacitor C75 both connected with the diode D3, the other end of the capacitor C74 connected with GND, and the other end of the resistor R141 connected with Vin; the SS pin of U13 connected with the diode D3 through a resistor R149;

[0007] The FB pin of U13 is connected with resistor R144, resistor R147 and polarized capacitor E5, the other end of resistor R144 is connected with GND, polarized capacitor E5 is connected with GND through resistor R142, the other end of resistor R147 is connected with resistor R283 and the D1 pin of field effect transistor Q18A, the other end of resistor R283 and the S1 pin of field effect transistor Q18A are connected with resistor R280, the G1 pin of field effect transistor Q18A is connected with the other end of resistor R280, the other end of resistor R280 is connected with the collector of triode Q17, the base of triode Q17 is connected with the D2 pin of field effect transistor Q18B through resistor R260, the emitter of triode Q17 is connected with +3.3V, +3.3V is also connected with the D2 pin of field effect transistor Q18B through resistor R236, the S2 pin of field effect transistor Q18B is connected with GND, the G2 pin of field effect transistor Q18B is connected with signal POWER_SEL1, and signal POWER_SEL1 is connected with XMOS.

[0008] The boost switching circuit comprises 6-pin SOT23 current mode boost converter U1, the VIN pin and the EN pin of U1 are connected with +6.5V, +6.5V is connected with GND through capacitor C69; the GND pin of U1 is connected with GND; the SW pin of U1 is connected with the 1 pin of diode D2 and inductor L6, the other end of inductor L6 is connected with +6.5V, the 2 pin of diode D2 is connected with VDD through resistor R140; the FB pin of U1 is connected with resistor R145, resistor R150 and polarized capacitor E8, the other end of resistor R145 is connected with the 2 pin of diode D2, the other end of polarized capacitor E8 is connected with the 2 pin of diode D2 through resistor R146, the other end of resistor R150 is connected with resistor R302 and the D1 pin of field effect transistor Q18A, the other end of resistor R302 and the S1 pin of field effect transistor Q18A are connected with GND, the G1 pin of field effect transistor Q18A is connected with resistor R311 and resistor R314, the other end of resistor R314 is connected with GND, the other end of resistor R311 is connected with signal POWER_SEL1, and signal POWER_SEL1 is connected with XMOS.

[0009] Further, the boost converter U1 is AH6910.

[0010] Further, the capacitor C67 is 100nF.

[0011] Further, the boost switching circuit further comprises capacitor C78, polarized capacitor E7 and capacitor C79, one end of capacitor C78, polarized capacitor E7 and capacitor C79 is connected with GND, the other end of capacitor C78, the other end of polarized capacitor E7 and the other end of capacitor C79 are connected with VEE through resistor R151, and resistor R151 is also connected with the 1 pin of diode D3.

[0012] Further, the boost switching circuit further comprises a capacitor C70, a capacitor C72, a polarity capacitor E4, a capacitor C71 and a capacitor C73, one end of the capacitor C70, the capacitor C72, the polarity capacitor E4, the capacitor C71 and the capacitor C73 is connected to the pin 2 of the diode D2, and the other end of the capacitor C70, the capacitor C72, the polarity capacitor E4, the capacitor C71 and the capacitor C73 is connected to the GND.

[0013] Further, the diode D2 and the diode D3 are B5819W, and the field effect transistor Q19A, the field effect transistor Q18A and the field effect transistor Q18B are 2N7002DW.

[0014] By adopting the technical scheme, the audio circuit voltage switching circuit has the advantages that:

[0015] The device has simple circuit structure, easy replacement of parts, supports low-power and high-power modes, can meet different needs of users, and can diversify the control mode to realize real-time switching of analog circuit voltage step-up and step-down.

[0016] Meanwhile, the manufacturing cost is low, and two different voltages are required for normal operation, in which case two DCDCs are required to switch different voltages, and two DCDCs are required to switch different negative voltages, so that the cost is doubled, but if the present scheme is used, half of the cost can be saved, and therefore the present scheme has high application value. BRIEF DESCRIPTION OF DRAWINGS

[0017] Figure 1 The utility model discloses a boost switching circuit principle diagram.

[0018] Figure 2 The utility model discloses a boost switching circuit principle diagram.

[0019] Figure 3 It is the Vout formula calculation diagram of data table. PREFERRED EMBODIMENT

[0020] The utility model will be further explained in detail in connection with the embodiment.

[0021] An analog circuit voltage switching circuit, like Figure 1 、 Figure 2 , comprising a step-down switching circuit and a step-up switching circuit,

[0022] Like Figure 1The buck switching circuit includes a buck converter U13, a capacitor C67 connected between the BOOT pin of U13 and the SW pin of U13, the SW pin of U13 connected to an inductor L7, the other end of the inductor L7 connected to GND; the GND pin and the PGND pin of U13 both connected to GND through a diode D3; the COMP pin of U13 connected to a capacitor C77 and then to a resistor R148, and then to the diode D3; the EN pin of U13 connected to a resistor R143, the other end of the resistor R143 connected to the VIN pin of U13; the VIN pin of U13 also connected to a capacitor C76, a capacitor C75, a capacitor C74, and a resistor R141, the other end of the capacitor C76 and the other end of the capacitor C75 both connected to the diode D3, the other end of the capacitor C74 connected to GND, and the other end of the resistor R141 connected to Vin; and the SS pin of U13 connected to the diode D3 through a resistor R149.

[0023] The FB pin of U13 connected to a resistor R144, a resistor R147, and a polarity capacitor E5, the other end of the resistor R144 connected to GND, the polarity capacitor E5 connected to GND through a resistor R142, the other end of the resistor R147 connected to a resistor R283 and the D1 pin of a field effect transistor Q18A, the other end of the resistor R283 and the S1 pin of the field effect transistor Q18A both connected to a resistor R280, the G1 pin of the field effect transistor Q18A connected to the other end of the resistor R280, the other end of the resistor R280 connected to the collector of a triode Q17, the base of the triode Q17 connected to the D2 pin of a field effect transistor Q18B through a resistor R260, the emitter of the triode Q17 connected to +3.3V, +3.3V also connected to the D2 pin of the field effect transistor Q18B through a resistor R236, the S2 pin of the field effect transistor Q18B connected to GND, and the G2 pin of the field effect transistor Q18B connected to a signal POWER_SEL1, and the signal POWER_SEL1 connected to XMOS.

[0024] The buck switching circuit also includes a capacitor C78, a polarity capacitor E7, and a capacitor C79, one end of the capacitor C78, the polarity capacitor E7, and the capacitor C79 all connected to GND, the other end of the capacitor C78, the other end of the polarity capacitor E7, and the other end of the capacitor C79 all connected to VEE through a resistor R151, and the resistor R151 also connected to the 1 pin of the diode D3.

[0025] As Figure 2The boost switching circuit includes a 6-pin SOT23 current mode boost converter U1, the VIN pin and the EN pin of U1 are connected to +6.5V, +6.5V is connected to GND through capacitor C69; the GND pin of U1 is connected to GND; the SW pin of U1 is connected to the 1 pin of diode D2 and inductor L6, the other end of inductor L6 is connected to +6.5V, the 2 pin of diode D2 is connected to VDD through resistor R140; the FB pin of U1 is connected to resistor R145, resistor R150 and polarized capacitor E8, the other end of resistor R145 is connected to the 2 pin of diode D2, the other end of polarized capacitor E8 is connected to the 2 pin of diode D2 through resistor R146, the other end of resistor R150 is connected to resistor R302 and the D1 pin of field effect transistor Q18A, the other end of resistor R302 and the S1 pin of field effect transistor Q18A are connected to GND, the G1 pin of field effect transistor Q18A is connected to resistor R311 and resistor R314, the other end of resistor R314 is connected to GND, the other end of resistor R311 is connected to signal POWER_SEL1, and signal POWER_SEL1 is connected to XMOS.

[0026] The boost switching circuit further includes capacitor C70, capacitor C72, polarized capacitor E4, capacitor C71 and capacitor C73, one end of capacitor C70, capacitor C72, polarized capacitor E4, capacitor C71 and capacitor C73 is connected to the 2 pin of diode D2, and the other end of capacitor C70, capacitor C72, polarized capacitor E4, capacitor C71 and capacitor C73 is connected to GND.

[0027] In the selection, the step-down converter U13 is TMI3343B, the step-up converter U1 is AH6910, and the capacitor C67 is 100nF. Diode D2 and diode D3 are both B5819W, and field effect transistor Q19A, field effect transistor Q18A and field effect transistor Q18B are all 2N7002DW.

[0028] Electronic component introduction:

[0029] 1. TMI3343B is a 4.5V to 30V wide input voltage, high efficiency current mode, synchronous step-down DC / DC converter, which can provide 3A switching frequency adjustable current 50kHz to 1.5MHz. TMI3343B integrates main switch and synchronous switch with low RDS (open) to minimize conduction loss. The device integrates 120mΩ high side and 80mΩ low side power MOS, and has advanced functions including UVLO, thermal shutdown, soft start, input OVP.

[0030] Principle:

[0031] TMI3343B uses +12V input voltage.

[0032] BOOT high side gate driver boot pin, provides power supply for high side LDMOS gate driver. Connect a 100nF capacitor between BOOT and SW switch pin.

[0033] SW switch pin, connected to an external inductor L7.

[0034] GND pin is connected to ground.

[0035] COMP is an external compensation pin.

[0036] EN is an enable pin. Drive EN to 1.5V or above to start, drive EN to 0.4V or below to stop, but do not float EN.

[0037] Connect the SS pin to an external resistor R149 to adjust the switching frequency device.

[0038] FB is a feedback pin, connected to resistors R144, R147, R283, when POWER_SEL1 through XMOS control IO is high, Q18B S2 and D2 pins are turned on, Q17 2 pin is low, Q17 is turned on, Q18A G1 pin is high, Q18A S1 and D1 pins are turned on, at this time the feedback pin FB is connected to R144, R147 two feedback resistors, TMI3343B output voltage is -15.04V, the calculation formula is from Figure 3 the data table formula R1=R2·(VOUT / VREF-1) is fitted into the schematic diagram, R144=R147·(VOUT / VREF-1)>>> known VREF=0.8V, R144=178K, R147=10K, thus Vout={(R144 / R147)+1}*0.8=-15.04V. When POWER_SEL1 through XMOS control IO is low, Q18(Q18B, Q18A), Q17 are not turned on, at this time the feedback pin FB is connected to R144, R147, R283 three feedback resistors, TMI3343B output voltage is -6.99V. The calculation formula is from Figure 3 the data table formula R1=R2·(VOUT / VREF-1) is fitted into the schematic diagram, R144=(R147+R283)·(VOUT / VREF-1)>>> known VREF=0.8V, R144=178K, R147=10K, R283=13K, thus Vout={(R144 / (R147+R283)+1}*0.8=-6.99V. TMI3343B REF=0.8.

[0039] 2. AH6910 is a constant frequency, 6-pin SOT23 current-mode step-up converter for small, low-power applications. The switching frequency is 1.2 MHz, allowing the use of small, low-cost capacitors and inductors with a height of up to 2 mm. Internal soft-start produces a small inrush current and prolongs battery life. Features include automatic switching to pulse frequency modulation mode at light loads, under-voltage lockout, current limit, and thermal overload protection to prevent damage in the event of an output overload. There is a small 6-pin SOT-23 package.

[0040] Principle:

[0041] AH6910 uses a +6.5V input voltage.

[0042] The SW pin is the power switch output. The SW pin is the drain of the internal MOSFET switch, which connects the power inductor and output rectifier to the SW pin. The SW pin can swing between GND and 28V.

[0043] The GND pin is connected to ground.

[0044] The EN pin is the regulator on / off control input. A high input at EN turns it on, and a low input turns it off. When not in use, connect EN to the input power for automatic start-up. The external control level is also connected to the 2 pin of Q2, one end of R311 POWER_SEL1, which controls the voltage switching of the positive and negative voltage chips simultaneously, achieving synchronous voltage switching. When POWER_SEL1 is high, the output voltage is +15.04V, and when POWER_SEL1 is low, the output voltage is +6.99V.

[0045] The FB pin is the feedback input. The FB pin voltage is 0.6V, and a resistor divider is connected to the FB pin. When POWER_SEL1 is high through XMOS control IO, the D1 and S1 pins of Q19 are turned on, and at this time the FB pin is connected to resistor R145, resistor R150, and the AH6910 output voltage is +15V. When POWER_SEL1 is low through XMOS control IO, at this time the FB pin is connected to resistor R145, resistor R150, and resistor R302, and the AH6910 output voltage is +7.02V. The REF of AH6910 is 0.6. The calculation method of the positive voltage DCDC output voltage is the same as that of the negative voltage, except that the voltage of VFB is 0.6V.

[0046] In summary: through this circuit, a real-time switching of analog circuit voltage step-up and step-down is realized.

Claims

1. An analog circuit voltage switching circuit, characterized by: The buck switching circuit includes a buck converter U13, a capacitor C67 is connected between the BOOT pin of U13 and the SW pin, the SW pin of U13 is connected with an inductor L7, the other end of L7 is connected with GND; the GND pin and the PGND pin of U13 are connected with GND through a diode D3; the COMP pin of U13 is connected with a capacitor C77 and a resistor R148 in sequence, and then connected with the diode D3; the EN pin of U13 is connected with a resistor R143, and the other end of R143 is connected with the VIN pin of U13; the VIN pin of U13 is also connected with a capacitor C76, a capacitor C75, a capacitor C74 and a resistor R141 respectively, the other end of C76 and the other end of C75 are connected with the diode D3, the other end of C74 is connected with GND, and the other end of R141 is connected with Vin; the SS pin of U13 is connected with the diode D3 through a resistor R149; The FB pin of U13 is connected with a resistor R144, a resistor R147 and a polarity capacitor E5, the other end of R144 is connected with GND, the polarity capacitor E5 is connected with GND through a resistor R142, the other end of R147 is connected with a resistor R283 and the D1 pin of a field effect transistor Q18A respectively, the other end of R283 and the S1 pin of Q18A are connected with a resistor R280, the G1 pin of Q18A is connected with the other end of R280, the other end of R280 is connected with the collector of a triode Q17, the base of Q17 is connected with the D2 pin of a field effect transistor Q18B through a resistor R260, the emitter of Q17 is connected with +3.3V, +3.3V is also connected with the D2 pin of Q18B through a resistor R236, the S2 pin of Q18B is connected with GND, the G2 pin of Q18B is connected with a signal POWER_SEL1, and the signal POWER_SEL1 is connected with XMOS; The boost switching circuit includes a 6-pin SOT23 current mode boost converter U1, the VIN pin and the EN pin of U1 are connected with +6.5V, and +6.5V is connected with GND through a capacitor C69; the GND pin of U1 is connected with GND; the SW pin of U1 is connected with the 1 pin of a diode D2 and an inductor L6, the other end of L6 is connected with +6.5V, the 2 pin of D2 is connected with VDD through a resistor R140; the FB pin of U1 is connected with a resistor R145, a resistor R150 and a polarity capacitor E8, the other end of R145 is connected with the 2 pin of D2, the other end of E8 is connected with the 2 pin of D2 through a resistor R146, the other end of R150 is connected with a resistor R302 and the D1 pin of a field effect transistor Q18A, the other end of R302 and the S1 pin of Q18A are connected with GND, the G1 pin of Q18A is connected with a resistor R311 and a resistor R314, the other end of R314 is connected with GND, the other end of R311 is connected with a signal POWER_SEL1, and the signal POWER_SEL1 is connected with XMOS. ​ 2. An analog circuit voltage switching circuit according to claim 1, characterized in that: The step-down converter U13 is TMI3343B, and the step-up converter U1 is AH6910.

3. The analog circuit voltage switching circuit of claim 1, wherein: The capacitor C67 is 100 nF.

4. The analog circuit voltage switching circuit of claim 1, wherein: The step-down switching circuit further includes a capacitor C78, a polarity capacitor E7, and a capacitor C79. One end of the capacitor C78, the polarity capacitor E7, and the capacitor C79 is connected to GND. The other end of the capacitor C78, the other end of the polarity capacitor E7, and the other end of the capacitor C79 are connected to VEE through a resistor R151. The resistor R151 is also connected to a diode D3.

5. The analog circuit voltage switching circuit of claim 1, wherein: The step-up switching circuit further includes a capacitor C70, a capacitor C72, a polarity capacitor E4, a capacitor C71, and a capacitor C73. One end of the capacitor C70, the capacitor C72, the polarity capacitor E4, the capacitor C71, and the capacitor C73 is connected to pin 2 of the diode D2. The other end of the capacitor C70, the capacitor C72, the polarity capacitor E4, the capacitor C71, and the capacitor C73 is connected to GND.

6. An analog circuit voltage switching circuit according to any one of claims 1-5, characterized in that: The diode D2 and the diode D3 are both B5819W. The field effect transistor Q19A, the field effect transistor Q18A, and the field effect transistor Q18B are all 2N7002DW.

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