TPS54120 - Low-Noise 1A DC-DC + LDO Supply | TI
料号： TPS54120RGYR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $6.1 | $6.10 |
| 10 | $5.49 | $54.90 |
| 100 | $4.72 | $472.00 |
| 500 | $4.1 | $2,050.00 |
| 1,000 | $3.66 | $3,660.00 |
TPS54120RGYR 概述
A power supply with an integrated DC-DC converter and LDO is a hybrid power management architecture within the voltage regulator family of power management ICs: the buck converter performs efficient step-down conversion, while the downstream LDO provides high power-supply rejection (PSR) and low output noise for sensitive loads. This two-stage approach in one IC eliminates the discrete two-chip design effort and is essential for powering clocking distribution, data converters, and RF circuits.
Key features include adjustable output voltage up to 6.0V via external resistors, soft-start, switching-frequency synchronization to an external clock, spread-spectrum clocking (SSC) for EMI reduction, power-good output, output discharge, fixed UVLO, overcurrent protection, and synchronous rectification. The fully configurable converter and LDO allow a wide range of low-noise rail designs from a single device.
Architecturally, the proprietary interaction between the buck stage and the LDO optimizes the efficiency-versus-noise trade-off: the converter handles the bulk voltage transformation, keeping LDO dropout small so PSR remains high with minimal efficiency penalty. The 24-VQFN (RGY) package provides a compact footprint with good thermal performance for space-constrained designs.
Typical applications include telecom infrastructure, pico and femto base stations, and powering sensitive clocking distribution such as PLLs, VCOs, and high-speed ADCs and DACs, where clean rails directly improve phase noise and SNR.
Design tip: keep the switching node short to minimize EMI, bypass the LDO output with a low-ESR ceramic capacitor for stability, and use the soft-start pin to control inrush current at power-up. Prices referenced are as of 2026-08-29.
直接替换替代料： TPS54120RGYR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
该产品暂无直接替换替代料。
请求替代料TPS54120RGYR 最大额定值与电气特性
| 拓扑 | Step-Down (Buck) DC-DC + Linear (LDO) |
| 输出数量 | 2 |
| 输入电压范围 | 4.5 V to 17 V |
| 输出电压范围 | Adjustable up to 6.0 V |
| Output Current | 1 A |
| 开关频率 | 200 kHz to 1.2 MHz |
| 同步整流 | Yes |
| 软启动 | Adjustable |
| Frequency Synchronization | Yes |
| Spread-Spectrum Clocking (SSC) | Yes |
| Protection Features | Overcurrent, fixed UVLO |
| 控制特性 | Enable, Power Good, Output Discharge |
| 封装 | 24-VQFN (5.5 x 3.5 mm) |
| 安装类型 | Surface Mount |
| RoHS 状态 | Compliant |
TPS54120RGYR 引脚配置
| 引脚 1 | BOOT — Bootstrap for high-side gate driver |
| 引脚 2 | PH — Switching node of buck converter |
| 引脚 3 | VIN — Input supply, 4.5V to 17V |
| 引脚 4 | EN — Enable input |
| 引脚 5 | SS/TR — Soft-start / tracking |
| 引脚 6 | RT/CLK — Frequency setting / external clock sync |
| 引脚 7 | PGND — Power ground |
| 引脚 8 | VSENSE — Buck feedback voltage sense |
| 引脚 9 | PWRGD — Power-good open-drain output |
| 引脚 10 | LDOIN — LDO input from converter output |
| 引脚 11 | LDOOUT — LDO regulated output |
| 引脚 12 | AGND — Analog ground |
典型应用
TPS54120RGYR 适用于 6 应用s: Telecom Infrastructure Power, Pico and Femto Base Stations, Clocking Distribution (PLL/VCO), High-Speed ADC/DAC Analog Rails, Industrial 12V Bus Point-of-Load, Test and Measurement Instruments.
Telecom Infrastructure Power
The TPS54120 fits telecom infrastructure rails because its 4.5V to 17V input directly accepts 12V distributed bus voltages while delivering a regulated, low-noise output up to 6.0V at 1A. The integrated buck plus high-PSR LDO architecture suppresses switching ripple so downstream line cards and clock circuits see a clean supply. Spread-spectrum clocking and 200kHz to 1.2MHz frequency synchronization help the system pass EMC requirements in dense chassis environments.
推荐
Pico and Femto Base Stations
In pico and femto base stations, board area and noise are both critical. The TPS54120 consolidates a buck converter and LDO into a single 24-VQFN (5.5x3.5 mm) footprint, cutting BOM count versus a discrete two-chip solution. Its high power-supply rejection keeps the local oscillator and transceiver supply quiet, while fixed UVLO and overcurrent protection add robustness for outdoor small-cell hardware running from 12V feeds.
推荐
Clocking Distribution (PLL/VCO)
The TPS54120 is explicitly targeted at powering sensitive clocking distribution such as PLLs and VCOs. The LDO stage rejects ripple from the internal synchronous buck, so phase-noise degradation from supply modulation is minimized - directly improving jitter performance. Adjustable output up to 6.0V supports common clock-IC core voltages, and the power-good pin enables rail monitoring in redundant clock trees. Frequency synchronization keeps the switching tone out of sensitive measurement bands.
推荐
High-Speed ADC/DAC Analog Rails
High-speed data converters require analog supply rails with low noise and high PSR to preserve SNR. The TPS54120 supplies up to 1A at up to 6.0V with the LDO stage filtering the buck ripple, providing the clean AVDD rail converters need. Bypassing the LDO output with low-ESR ceramic capacitors maintains stability and low output impedance across the converter's sampling bandwidth. The compact VQFN-24 keeps the supply close to the converter.
推荐
Industrial 12V Bus Point-of-Load
The TPS54120's 4.5V to 17V input range accommodates industrial 12V buses with tolerance for transients, making it a compact point-of-load supply for PLC I/O, sensors, and mixed-signal boards. Synchronous rectification improves light-load efficiency, and adjustable soft-start controls inrush on shared rails. Overcurrent protection and output discharge simplify fault handling in multi-rail industrial systems where controlled shutdown sequencing matters.
推荐
Test and Measurement Instruments
Bench instruments and modules need quiet local supplies near clock oscillators and precision analog front ends. The TPS54120 provides a single-IC solution: the buck stage handles efficient step-down from 12V, while the high-PSR LDO delivers the low-noise rail that keeps spectrum-analyzer-grade signal chains free of spurs. Adjustable switching frequency allows designers to place residual switching tones outside the instrument's measurement bands.
推荐
推荐产品汇总
工程参考数据： TPS54120RGYR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | TPS62912 | TPS54620 | TPS74801QDRCRQ1 |
|---|---|---|---|---|
| Package | 24-VQFN (5.5x3.5 mm) | SOT-583 (DRL) | SOIC-8 (D) | VQFN-24 (DRC) |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Architecture | Buck + LDO integrated | Buck only | Buck only | LDO only |
| Output Voltage | Adjustable up to 6.0 V | Adjustable/Fixed | Adjustable to 6 V | Adjustable, up to 15 V |
| SSC / Sync | Yes | Yes | Sync only | N/A |
| Drop-in Replacement | - | No (redesign + external LDO) | No (needs external LDO) | No (LDO only) |
关键差异点
- Single-IC buck + LDO integration （对比 TPS62912)
- 200kHz-1.2MHz adjustable frequency with SSC （对比 TPS54620)
- Compact 5.5x3.5 mm VQFN-24 for a complete two-stage supply （对比 TPS74801QDRCRQ1)
设计说明
Keep the PH switching node and BOOT capacitor connections as short and compact as possible to minimize EMI and parasitic ringing. Place VIN decoupling ceramic capacitors within 2-3 mm of the VIN pin, and route the power ground (PGND) return directly under the switching loop. Use the exposed pad as the main thermal and ground connection with a solid via array to the ground plane.
Bypass the LDO output with a low-ESR ceramic capacitor per the datasheet's stability requirements to ensure loop stability and low output impedance. Set the soft-start capacitor to limit inrush on shared 12V rails, and use the adjustable RT/CLK resistor to place the switching frequency away from sensitive RF bands or synchronize to a system clock.
Do not exceed 17V input - the device is intended for 12V buses with limited headroom, not wide Vin applications. Verify the LDO input-to-output headroom: if the buck output is set too close to the LDO output, PSR degrades. Ensure the output divider uses 1% or better resistors to keep the adjustable output within the 6.0V maximum.
合规信息
RoHS compliant per TI product listing. AEC-Q100 qualification not indicated for this part in the provided data.
