DATA SHEET
TPS54A20 8V 至 14V 输入、10A、频率高达 10MHz 的 SWIFT降压转换器
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1 特性
2 应用
- 电信、基站和通信设备
- 存储、固态硬盘 (SSD)、DDR 存储器、交换机、集线器、路由器和其他网络设备
- 薄型/背面板安装（高度低于 2mm）
3 说明
TPS54A20 是一款双相同步串联电容降压转换器，专为输入电压轨为 12V 的小尺寸、低电压 应用 而设计。该器件采用独特的拓扑结构，将开关电容电路与双相降压转换器融为一体，而且拥有诸多优势，其中包括电感间的自动电流均衡、较低的开关损耗（支持高频 (HF) 操作）以及通过串联电容实现降压。与 TPS54A20 搭配使用的低值薄型电感显著缩减了解决方案的面积和高度。该器件采用一种自适应导通时间控制架构，可在高达 10MHz 的工作频率下提供快速瞬态响应和精确稳压。通过使用锁相环 (PLL) 来锁定基准振荡器的开关信号，从而维持稳定状态下的固定频率操作。
器件信息(1)
| 器件型号 | 封装 | 封装尺寸（标称值） |
|---|---|---|
| TPS54A20 | VQFN（20 引脚） | 3.5mm x 4mm |
- 要了解所有可用封装，请见数据表末尾的可订购米6体育平台手机版_好二三四附录。
简化电路原理图
效率与负载电流间的关系
1.8 VOUT，2MHz（每相位），外部 VG+，3.2mm x 2.5mm x 1.2mm 电感
5 Pin Configuration and Functions
RNJ Package
VQFN (20 Pin)
Top View
Pin Functions
| PIN | I/O(1) | DESCRIPTION | |
|---|---|---|---|
| NAME | NO. | ||
| AGND | 1 | G | Analog signal ground of the IC. AGND should be connected to PGND and VG- at a single point on PCB (e.g. underneath the IC). |
| BOOTA | 8 | S | Bootstrap capacitor node for phase A high-side MOSFET gate driver. Connect the bootstrap capacitor from this pin to the SCAP pin (pin 9). |
| BOOTB | 10 | S | Bootstrap capacitor node for phase B high-side MOSFET gate driver. Connect the bootstrap capacitor from this pin to the SWB pin. |
| EN | 4 | I | Enable pin. Floating this pin will enable the IC. Pull below 1.23V to enter shutdown mode. Can also be used to adjust the input undervoltage lockout above 8 V with two resistors. |
| FB | 18 | I | Feedback pin for voltage regulation. Connect this pin to the center tap of a resistor divider to set the output voltage. |
| ILIM | 5 | I | Current limit programming pin. A resistor between this pin and ground sets the current limit. If no resistor is included, the default load current limit is 15 A. |
| NC | 11 | No connect. This pin is not electrically connected to the IC and is included for board level reliability (BLR) purposes. Connect this pin to the SCAP trace. | |
| PGND | 2 | G | Power ground of the IC. PGND should be connected to AGND and VG- at a single point on PCB (e.g. underneath the IC). Thermal vias to internal ground planes should be added beneath this pin. |
| PGOOD | 15 | O | Power good indicator. This pin is an open-drain output and will assert low if the output voltage is greater than ±5% away from the desired value or due to thermal shutdown, over-voltage/under-voltage, EN shutdown, or during soft start. A pull-up resistor can be connected between PGOOD and VG+ or an external logic supply pin. |
| SCAP | 9,20 | O | Series capacitor pin. Connect a ceramic capacitor from pin 20 to the SWA pin. |
| SS/FSEL | 6 | I | Soft start/frequency select pin. Connect a resistor from this pin to ground to set the soft-start time and the switching frequency. If no resistor is provided, the default setting of 4MHz oscillator frequency and 512µs soft start time is used. |
| SWA | 13 | O | Switching node for phase A. Connect an inductor from this pin to the output capacitors. |
| SWB | 12 | O | Switching node for phase B. Connect an inductor from this pin to the output capacitors. |
| SYNC | 14 | I | External clock synchronization pin. An external clock signal can be connected to this pin to synchronize the oscillator frequency (within ±10% of the nominal frequency set via SS/FSEL). |
| TON | 19 | I | On-time selection. An external resistor from this pin to the AGND pin programs the nominal on-time of the high side switches. |
| VG+ | 16 | S | Gate driver positive supply pin. Connect a bypass capacitor from this pin to VG-. To improve converter efficiency, the internal regulator can be overridden by connecting an external 5V supply to this pin. This supply rail also provides power to the control circuitry. |
| VG- | 17 | G | Gate driver supply return pin. VG- should be connected to PGND and AGND at a single point on PCB (e.g. underneath the IC). |
| VGA | 7 | S | High side phase A gate driver supply pin. Connect a bypass capacitor from this pin to ground. |
| VIN | 3 | I | The power input pin to the IC. Connect VIN to a supply voltage between 8 V and 14 V. |
(1) I = Input, O = Output, S = Supply, G = Ground Return