MIC2132和MIC2133对比和电路设计要点注意
这次Digikey主推料MIC2122和MIC2123是可以满足兼容设计的，我们先进行参数对比。
一、芯片DS关键参数
如下我们先对两者进行主要参数对比:
| 第 1 列 | 第 2 列 | 第 3 列 | 第 4 列 |
|---|---|---|---|
| Value / Features | MIC2132YML | MIC2133YML | Note |
| Hyper Light Load | 无 | 有 | 轻载自动降频、跳脉冲 |
| Multiphase | Max. 8 phase | Fixed 2 phase | |
| DROOP/AVP Pin | 无 | 有 | 主动电压定位，省输出电容 |
| 引脚定义 | NPI、ONR、APO | PSH、TEMP、DR | Different |
| Vin | 8 V – 75 V | Same | |
| Vout | 0.6 V – 28 V | Same | |
| Switch Freq. | 100 k – 1 MHz 可设 | RT/CLK 引脚 | |
| 外置MOS | 外置 MOSFET | 根据不同的MOS满足不同需求， 当前我看到的MOS最大可以做到35A | |
| Compact Size | 32-VQFN 5 mm×5 mm | 引脚排列完全一致 | |
| Tj | –40 °C ~ +125 °C | 车规 AEC-Q100 | |
| Applications | 大电流CPU/DPU | 车载/工业/IOT | MIC2132适合 60 A++需求；MIC2133适合 20-40 A |
封装、引脚排布、焊盘 100 % 相同 —— 两颗芯片在 PCB 上可以做到pin-to-pin compatible。
二、pin参数对比
| 第 1 列 | 第 2 列 | 第 3 列 | 第 4 列 | E | F | G | H |
|---|---|---|---|---|---|---|---|
| Pin | Name | MIC2132 | MIC2133 | 差异说明 | |||
| 1 | CSN2 | Current Sense Return pin for Phase 2. Connect Kelvin connection from the low-side FET source to CSN2 to avoid ground drops due to high current. | 相同 | ||||
| 2 | CSP2 | Current Sense Positive pin for Phase 2. Connect Kelvin connection from the low-side FET drain to CSP2 to avoid ground drops due to high current. | 相同 | ||||
| 3 | CSN1 | Current Sense Return pin for Phase 1. Connect Kelvin connection from the low-side FET source to CSN1 to avoid ground drops due to high current. | 相同 | ||||
| 4 | CSP1 | Current Sense Positive pin for Phase 1. Connect Kelvin connection from the low-side FET drain to CSP1 to avoid ground drops due to high current. | 相同 | ||||
| 5 | ILIM | Current Limit Adjust Input pin. Connect a resistor from ILIM to AGND to set the current limit. Refer to Section 4.5.2 “Current Limit” for more details. Both channels share the same current limit threshold. When connected in a stackable application, all ILIM pins are tied together, sharing common resistor sized for voltage drop, corresponding to current limit per phase. | 相同 | ||||
| 6 | CSH | Average Current Sense Voltage Output pin. Used for current sharing; see Section 4.5.1 “Current Balancing Between Phases” and Section 4.5.9 “Adaptive Voltage Positioning (AVP)”, also Known as Droop Function (Recommended for CSA Only). Connect 100 pF capacitor from CSH to AGND in stackable applications, tie CSH pins together. | 相同 | ||||
| 7 | EN | Active-High Enable Input pin. 7.5V compatible with 1.2V precision threshold. Pull EN to GND to disable the buck converter output. Connect to VIN for always-on operation. EN can be used for power sequencing and as a UVLO adjustment input. For a precision UVLO, put an appropriately sized resistor divider from VIN to AGND and tie the midpoint to the EN pin. | 相同 | ||||
| 8 | VIN | Input Voltage to Controller pin. Connect to VIN through 1.2/10 resistor. Connect 1 μF capacitor from this pin to PGND. | 相同 | ||||
| 9 | VDD | 5V LDO Output pin for the MIC2132/3 control logic circuit. Connect a minimum 2.2 μF low-ESR ceramic capacitor from VDD to AGND. | 相同 | ||||
| 10 | AGND | Analog Ground pin. Reference node for all the control logic circuits inside the MIC2132/3. Connect AGND to PGND at one point | 相同 | ||||
| 11 | EXTVDD | Auxiliary LDO Input pin. Connected to a supply higher than 4.7V (typ) to bypass the internal high-voltage 5V LDO or leave unconnected/connected to ground when the EXTVDD pin is not used. Connect a 2.2 μF low-ESR ceramic capacitor between EXTVDD and AGND. EXTVDD can be connected to an external supply. | 相同 | ||||
| 12 | NPI or PSH | NPI - Negative Phase Input pin. Connect APO of previous MIC2132 to NPI for multiphase operation | PSH - Phase Shedding Threshold Programming pin. Connect a resistor from PSH to AGND. The voltage drop across the resistor decides the phase shedding threshold | Different | |||
| 13 | APO or TEMP | APO - Active Phase Output pin. Connect APO to the next MIC2132 NPI pin for multiphase operation | TEMP - Die Junction Temperature Sense Output pin from Internal Diode. Connect a 1 µF capacitor from the TEMP pin to AGND. | Different | |||
| 14 | ONR or OUT | ONR - On-Time Request pin. It is an input or an output pin. Connect the ONR pins of all MIC2132 devices connected for multiphase operation. It is an output for the host and an input for the secondaries. The ONR output on the host has a pull-up capability of ~1 kΩ. When FBS is connected to VDD, it is an input (secondary). | OUT - Output Voltage Sense pin. It is required to connect the OUTS pin to output through a 10 kΩ resistor and decouple to ground with a 100 nF capacitor for VOUT ≤ 5V. For VOUT > 5V, it is required to connect the OUTS pin through a resistive divider from VOUT to AGND. The OUTS pin will set the correct frequency adaptive to output voltage | Different | |||
| 15 | OUTS or DR | OUTS - Output Voltage Sense pin. It is required to connect the OUTS pin to output through a 10 kΩ resistor & decouple to ground with a 100 nF capacitor directly for VOUT ≤ 5V. For VOUT > 5V, it is required to connect the OUTS pin through a resistive divider from VOUT to AGND. The OUTS pin will set the correct frequency adaptive to the output voltage. | DR - Gate Driver Output pin for Output OVP Discharge MOSFET. One single event of overvoltage over the OVP upper threshold for a duration longer than 12 µs sets DR = High. The MIC2133 has to be restarted by EN or VIN cycling. | Different | |||
| 16 | BST1 | Phase 1 Bootstrap Capacitor Connection pin. The BST1 pin is the supply voltage input for the Phase 1 high-side MOSFET driver. Connect a 0.1 µF low-ESR ceramic capacitor between the BST1 pin and the SW1 pin. | 相同 | ||||
| 17 | DH1 | Phase 1 High-Side Gate Driver Output pin. Connect DH1 to the Phase 1 high-side MOSFET gate. | 相同 | ||||
| 18 | SW1 | Phase 1 Switch Node Output pin. Connect one terminal of the Phase 1 inductor to the SW1 node. | 相同 | ||||
| 19 | DL1 | Phase 1 Switch Node Output pin. Connect one terminal of the Phase 1 inductor to the SW1 node. | 相同 | ||||
| 20 | PGND | PGND is the return path for the low-side MOSFET current and for the low-side MOSFET driver. | 相同 | ||||
| 21 | PVDD | Supply pin for the Low-Side MOSFET Driver. Connected to VDD through a 2.2Ω series resistor. | 相同 | ||||
| 22 | DL2 | Phase 2 Low-Side Gate Driver Output pin. Connect DL2 to Phase 2 low-side MOSFET gate. | 相同 | ||||
| 23 | SW2 | Phase 2 Switch Node Output pin. Connect one terminal of the Phase 2 inductor to the SW2 node. | 相同 | ||||
| 24 | DH2 | Phase 2 High-Side Gate Driver Output Pin. Connect DH2 to the Phase 2 high-side MOSFET gate. | 相同 | ||||
| 25 | BST2 | Phase 2 Bootstrap Capacitor Connection pin. The BST2 pin is the supply voltage input for the phase 2 high-side MOSFET driver. Connect a 0.1 µF low-ESR ceramic capacitor between the BST2 pin and the SW2 pin. | 相同 | ||||
| 26 | PG | Open-Drain Power Good Output pin. PG is pulled to GND when the output voltage is below 80% of the target voltage. Pull-up to VDD through a 10 kΩ resistor to set logic to a high level when the output voltage is above 90% of the target voltage. | 相同 | ||||
| 27 | RIP_INJ | Ripple Injection Node pin. Connect series RC network from the RIP_INJ pin to FBS for injecting sufficient ripple for stable operation. Also connect a prepositioning resistor from this pin to AGND to set up the RIP_INJ pin voltage to its steady-state value. There is a 4.8 µA pull-up current when High-Z to preposition the common point of RINJ and CINJ. | 相同 | ||||
| 28 | FBS | Remote Feedback Input pin. | 相同 | ||||
| 29 | GFB | Ground Feedback Remote Sense pin. Connect Kelvin sense directly across the output capacitor ground through the low-side FB resistor ground connection. | 相同 | ||||
| 30 | SS | Soft Start Adjustment pin. Connect a capacitor from the SS pin to AGND to adjust the soft start time. See more details in Section 4.5.5 “Soft Start”. Connect an optional resistor across the SS pin to AGND for overshoot reduction during soft start. | 相同 | ||||
| 31 | FREQ | Frequency Programming Input pin. Connect to ground through resistor set to the same switching frequency for each phase. | 相同 | ||||
| 32 | DROOP | Analog Output DROOP pin. This pin is for implementing the “Adaptive Voltage Positioning” feature. Connect a resistor from the DROOP pin to the feedback resistor divider. The DROOP voltage is proportional with inductor current for load currents greater than 0A. | 相同 | ||||
| – | EP | Exposed Pad pin. Connect it to AGND. | 相同 | ||||
二、设计原理图注意要点
- MIC2132 官方支持堆叠（stacking）设计，datasheet明确给出：
-
最多4颗并联（即8 phase）- EV66F86A EVB是1颗2 phase;
-
通过 NPI / APO / ONR 三根级联线实现自动交错与均流；
-
芯片共用一颗 ILIM 电阻，保证电流限制点一致；
-
主从角色由 FBS 是否接 VDD 自动识别：
– 主机 FBS 接反馈分压器
– 从机 FBS 接 VDD
- 单颗MIC2132和2133的应用，对比如下:
- 为了实现使用MIC2132设计也兼容焊接MIC2133，我们可以做一张MIC2132的板，再把pin 12、13、14、15用 0 ohm 跳线留给 MIC2133的差异化电路设计部分；其余脚直接共用。