TPS51125RGER
Dual-Synchronous, Step-Down ControllerThe TPS51125RGER is a dual-synchronous, step-down controller from Texas Instruments. View the full TPS51125RGER datasheet below including key specifications, pinout, electrical characteristics, absolute maximum ratings.
Manufacturer
Texas Instruments
Category
Dual-Synchronous, Step-Down Controller
Package
24-VFQFN Exposed Pad
Lifecycle
Active
Key Specifications
| Parameter | Value |
|---|---|
| Clock Sync | No |
| Control Features | Enable, On Time Control, Power Good |
| Function | Step-Down |
| Mounting Type | Surface Mount |
| Number of Outputs | 2 |
| Operating Temperature | -40°C ~ 85°C (TA) |
| Output Configuration | Positive |
| Output Phases | 1 |
| Output Type | Transistor Driver |
| Package / Case | 24-VFQFN Exposed Pad |
| Supplier Device Package | 24-VQFN (4x4) |
| Synchronous Rectifier | Yes |
| Topology | Buck |
| Supply Voltage | 5.5V ~ 28V |
Overview
Part: TPS51125 — Texas Instruments
Type: Dual-Synchronous, Step-Down Controller
Description: A cost-effective, dual-synchronous buck controller targeted for notebook system power supply solutions, providing 5-V and 3.3-V LDOs, operating with 5.5 V to 28 V input and supporting 2 V to 5.5 V output.
Operating Conditions:
- Supply voltage: 5.5 V to 28 V
- Operating temperature: -40 to 85 °C
- Output voltage range: 2 V to 5.5 V
- LDO output current: 100 mA
Absolute Maximum Ratings:
- Max supply voltage: 30 V (VIN)
- Max junction temperature: 125 °C
Key Specs:
- VREF output voltage: 1.98 V to 2.02 V (I VREF = 0 A)
- VREG5 output voltage: 4.8 V to 5.2 V (VO1 = 0 V, I VREG5 < 100 mA, T A = 25°C)
- VREG3 output voltage: 3.2 V to 3.46 V (VO2 = 0 V, I VREG3 < 100 mA, T A = 25°C)
- VREG5 output current: 100 mA (VO1 = 0 V, VREG5 = 4.5 V)
- VREG3 output current: 100 mA (VO2 = 0 V, VREG3 = 3 V)
- VIN supply current (no load): 0.55 mA (Typ, T A = 25°C, VO1 = 0 V, VO2 = 0 V, EN0=open, ENTRIPx = 5 V, VFB1 = VFB2 = 2.05 V)
- Clock frequency (VCLK): 175 kHz to 325 kHz (Typ 270 kHz, T A = 25 °C)
- Minimum on time: 80 ns (Typ, T A = 25 °C)
Features:
- Wide Input Voltage Range: 5.5 V to 28 V
- Output Voltage Range: 2 V to 5.5 V
- Built-In 100-mA, 5-V and 3.3-V LDO With Switches
- Built-In 1% 2-V Reference Output
- With or Without Out-of-Audio™ Mode Selectable Light-Load and PWM-Only Operation
- Adaptive On-Time Control Architecture With Four Selectable Frequency Setting
- Built-In OVP/UVP/OCP
- Thermal Shutdown (Nonlatch)
Applications:
- Notebook Computers
- I/O Supplies
- System Power Supplies
Package:
- VQFN (24)
Features
- 1 · Wide Input Voltage Range: 5.5 V to 28 V
- Output Voltage Range: 2 V to 5.5 V
- Built-In 100-mA, 5-V and 3.3-V LDO With Switches
- Built-In 1% 2-V Reference Output
- With or Without Out-of-Audio™ Mode Selectable Light-Load and PWM-Only Operation
- Internal 1.6-ms Voltage Servo Soft-Start
- Adaptive On-Time Control Architecture With Four Selectable Frequency Setting
- 4500 ppm/°C RDS(on) Current Sensing
- Built-In Output Discharge
- Powergood Output
- Built-In OVP/UVP/OCP
- Thermal Shutdown (Nonlatch)
- QFN, 24-Pin (RGE)
Applications
- Notebook Computers
- I/O Supplies
- System Power Supplies
Pin Configuration
TPS51125RGER — QFN-24-EP(4x4) Pinout
| Pin Number | Pin Name | Type | Description |
|---|---|---|---|
| 1 | ENTRIP1 | I/O | Channel 1 and Channel 2 enable and OCL trip setting pins. Connect resistor from this pin to GND to set threshold for synchronous RDS(on) sense. Short to ground to shutdown a switcher channel. |
| 2 | VFB1 | I | Feedback voltage input for channel 1. |
| 3 | VREF | I | Reference voltage input. |
| 4 | TONSEL | I | On-time adjustment pin. 365 kHz/460 kHz: connect to VREG5; 300 kHz/375 kHz: connect to VREG3; 245 kHz/305 kHz: connect to VREF; 200 kHz/250 kHz: connect to GND. |
| 5 | VFB2 | I | Feedback voltage input for channel 2. |
| 6 | ENTRIP2 | I/O | Channel 1 and Channel 2 enable and OCL trip setting pins. Connect resistor from this pin to GND to set threshold for synchronous RDS(on) sense. Short to ground to shutdown a switcher channel. |
| 7 | VO2 | I | Switch node connection for low-side driver, current limit and control circuitry (Channel 2). |
| 8 | VREG3 | P | 3.3V regulated output. |
| 9 | VBST2 | I | Bootstrap voltage input for low-side driver (Channel 2). |
| 10 | DRVH2 | O | High-side N-channel MOSFET driver output. LL referenced driver. |
| 11 | LL2 | I | Switch node connection for high-side driver, current limit and control circuitry (Channel 2). |
| 12 | DRVL2 | O | Low-side N-channel MOSFET driver output. GND referenced driver. |
| 13 | EN0 | I/O | Master enable input. Open: LDOs on, ready to turn on VCLK and switcher channels. 620 kΩ to GND: enable both LDOs, VCLK off, ready to turn on switcher channels. GND: disable all circuits. |
| 14 | SKIPSEL | I | Selection pin for operation mode (OOA auto skip, auto skip modes). Connect to VREG3, VREG5, or VREF. |
| 15 | GND | P | Ground. |
| 16 | VIN | P | Input supply voltage. |
| 17 | VREG5 | P | 5V regulated output. |
| 18 | VCLK | O | Clock output. |
| 19 | DRVL1 | O | Low-side N-channel MOSFET driver output. GND referenced driver. |
| 20 | LL1 | I | Switch node connection for high-side driver, current limit and control circuitry (Channel 1). |
| 21 | DRVH1 | O | High-side N-channel MOSFET driver output. LL referenced driver. |
| 22 | VBST1 | I | Bootstrap voltage input for low-side driver (Channel 1). |
| 23 | PGOOD | O | Power Good window comparator output for channels 1 and 2 (logical AND). |
| 24 | VO1 | I | Switch node connection for low-side driver, current limit and control circuitry (Channel 1). |
| EP | GND | P | Exposed pad (thermal ground). |
Notes
- Package: QFN-24-EP (4×4 mm) with exposed pad.
- Pin numbering: Verified against the provided pin diagram (top view).
- Power pins: VIN (16), VREG3 (8), VREG5 (17), GND (15), and exposed pad (EP) all connect to ground or supply rails.
- Dual-channel design: Pins are organized for two independent switching channels (Channel 1: VO1, VBST1, LL1, DRVH1, DRVL1; Channel 2: VO2, VBST2, LL2, DRVH2, DRVL2).
- Bootstrap pins (VBST1, VBST2) require external capacitors for high-side driver operation.
Electrical Characteristics
over operating free-air temperature range, VIN = 12 V (unless otherwise noted)
| PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|---|
| SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT | SUPPLY CURRENT |
| I VIN1 | VIN supply current1 | VIN current, T A = 25°C, no load, VO1 = 0 V, VO2 = 0 V, EN0=open, ENTRIPx = 5 V, VFB1 = VFB2 = 2.05 V | 0.55 | 1 | mA | |
| I VIN2 | VIN supply current2 | VIN current, T A = 25°C, no load, VO1 = 5 V, VO2 = 3.3 V, EN0=open, ENTRIPx = 5 V, VFB1 = VFB2 = 2.05 V | 4 | 6.5 | μ A | |
| I VO1 | VO1 current | VO1 current, T A = 25°C, no load, VO1 = 5 V, VO2 = 3.3 V, EN0=open, ENTRIPx = 5 V, VFB1 = VFB2 = 2.05 V | 0.8 | 1.5 | mA | |
| I VO2 | VO2 current | VO2 current, T A = 25°C, no load, VO1 = 5 V, VO2 = 3.3 V, EN0=open, ENTRIPx = 5 V, VFB1 = VFB2 = 2.05 V | 12 | 100 | ||
| I VINSTBY | VIN standby current | VIN current, T A = 25°C, no load, EN0 = 1.2 V, ENTRIPx = 0 V | 95 | 250 | μ A | |
| I VINSDN | VIN shutdown current | VIN current, T A = 25°C, no load, EN0 = ENTRIPx = 0 V | 10 | 25 | ||
| VREF OUTPUT | VREF OUTPUT | VREF OUTPUT | VREF OUTPUT | VREF OUTPUT | VREF OUTPUT | VREF OUTPUT |
| V | VREF output voltage | I VREF = 0 A | 1.98 | 2.00 | 2.02 | V |
| VREF | -5 μ A < I VREF < 100 μ A | 1.97 | 2.00 | 2.03 | ||
| VREG5 OUTPUT | VREG5 OUTPUT | VREG5 OUTPUT | VREG5 OUTPUT | VREG5 OUTPUT | VREG5 OUTPUT | VREG5 OUTPUT |
| V VREG5 | VREG5 output voltage | VO1 = 0 V, I VREG5 < 100 mA, T A = 25°C | 4.8 | 5 | 5.2 | V |
| V VREG5 | VREG5 output voltage | VO1 = 0 V, I VREG5 < 100 mA, 6.5 V < VIN < 28 V | 4.75 | 5 | 5.25 | |
| VREG5 output current | VO1 = 0 V, I VREG5 < 50 mA, 5.5 V < VIN < 28 V | 4. 75 | 5 | 5.25 | ||
| I VREG5 | VO1 = 0 V, VREG5 = 4.5 V | 100 | 175 | 250 | mA | |
| Switch over threshold | Turns on | 4.55 | 4.7 | 4.85 | ||
| V TH5VSW | Hysteresis | 0.15 | 0.25 | 0.3 | V | |
| R 5VSW | 5 V SW R ON | VO1 = 5 V, I VREG5 = 100 mA | 1 | 3 | Ω | |
| VREG3 OUTPUT | VREG3 OUTPUT | VREG3 OUTPUT | VREG3 OUTPUT | VREG3 OUTPUT | VREG3 OUTPUT | VREG3 OUTPUT |
| V VREG3 | VREG3 output voltage | VO2 = 0 V, I VREG3 < 100 mA, T A = 25°C | 3.2 | 3.33 | 3.46 | V |
| V VREG3 | VREG3 output voltage | VO2 = 0 V, I VREG3 < 100 mA, 6.5 V < VIN < 28 V | 3.13 | 3.33 | 3.5 | |
| V VREG3 | VREG3 output voltage | VO2 = 0 V, I VREG3 < 50 mA, 5.5 V < VIN < 28 V | 3.13 | 3.33 | 3.5 | |
| I VREG3 | VREG3 output current | VO2 = 0 V, VREG3 = 3 V | 100 | 175 | 250 | mA |
| Turns on | 3.05 | 3.15 | 3.25 | |||
| V TH3VSW | Switch over threshold | Hysteresis | 0.1 | 0.2 | 0.25 | V |
| R 3VSW | 3 V SW R ON | VO2 = 3.3 V, I VREG3 = 100 mA | 1.5 | 4 | Ω | |
| INTERNAL REFERENCE VOLTAGE | INTERNAL REFERENCE VOLTAGE | INTERNAL REFERENCE VOLTAGE | INTERNAL REFERENCE VOLTAGE | INTERNAL REFERENCE VOLTAGE | INTERNAL REFERENCE VOLTAGE | INTERNAL REFERENCE VOLTAGE |
| V IREF | Internal reference voltage | I VREF = 0 A, beginning of ON state | 1.95 | 1.98 | 2.01 | |
| FB voltage, I VREF = 0 A, skip mode | 1.98 | 2.01 | 2.04 | |||
| V VFB | VFB regulation voltage | FB voltage, I VREF = 0 A, OOA mode (1) | 2.00 | 2.035 | 2.07 | V |
| V VFB | FB voltage, I VREF = 0 A, continuous conduction (1) | 2.00 | ||||
| I VFB | VFB input current | VFBx = 2.0 V, T A = 25°C | -20 | 20 | nA |
Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)
| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| Input voltage (1) | VBST1, VBST2 | -0.3 | 36 | V |
| Input voltage (1) | VIN | -0.3 | 30 | V |
| Input voltage (1) | LL1, LL2 | -2 | 30 | V |
| Input voltage (1) | LL1, LL2, pulse width < 20 ns | -5 | 30 | V |
| Input voltage (1) | VBST1, VBST2 (2) | -0.3 | 6 | V |
| Input voltage (1) | EN0, ENTRIP1, ENTRIP2, VFB1, VFB2, VO1, VO2, TONSEL, SKIPSEL | -0.3 | 6 | V |
| Output | DRVH1, DRVH2 | -1 | 36 | V |
| Output | DRVH1, DRVH2 (2) | -0.3 | 6 | V |
| Output | PGOOD, VCLK, VREG3, VREG5, VREF, DRVL1, DRVL2 | -0.3 | 6 | V |
| Junction temperature, T J | Junction temperature, T J | -40 | 125 | °C |
| Storage temperature, T stg | Storage temperature, T stg | -55 | 150 | °C |
Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| Supply voltage | VIN | 5.5 | 28 | |
| Input voltage | VBST1, VBST2 | -0.1 | 34 | |
| VBST1, VBST2 (with respect to LLx) | -0.1 | 5.5 | ||
| EN0, ENTRIP1, ENTRIP2, VFB1, VFB2, VO1, VO2, TONSEL, SKIPSEL | -0.1 | 5.5 | ||
| Output voltage | DRVH1, DRVH2 | -0.8 | 34 | V |
| Output voltage | DRVH1, DRVH2 (with respect to LLx) | -0.1 | 5.5 | V |
| Output voltage | LL1, LL2 | -1.8 | 28 | V |
| Output voltage | VREF, VREG3, VREG5 | -0.1 | 5.5 | V |
| Output voltage | PGOOD, VCLK, DRVL1, DRVL2 | -0.1 | 5.5 | V |
| Operating free-air temperature | Operating free-air temperature | -40 | 85 | °C |
Thermal Information
| THERMAL METRIC (1) | TPS51125 VQFN | UNIT | |
|---|---|---|---|
| 24 PINS | |||
| R θ JA | Junction-to-ambient thermal resistance | 34.2 | °C/W |
| R θ JC(top) | Junction-to-case (top) thermal resistance | 37.2 | °C/W |
| R θ JB | Junction-to-board thermal resistance | 12.4 | °C/W |
| ψ JT | Junction-to-top characterization parameter | 0.4 | °C/W |
| ψ JB | Junction-to-board characterization parameter | 12.4 | °C/W |
| R θ JC(bot) | Junction-to-case (bottom) thermal resistance | 2.8 | °C/W |
Typical Application
The TPS51125 is typically used as a dual-synchronous buck controller, which convert an input voltage ranging from 5.5 V to 28 V, to output voltage 5 V and 3.3 V respectively, targeted for notebook system-power supply solutions.
Related Variants
The following components are covered by the same datasheet.
| Part Number | Manufacturer | Package |
|---|---|---|
| TPS51125 | Texas Instruments | — |
| TPS51125RGER.A | Texas Instruments | — |
| TPS51125RGER.B | Texas Instruments | — |
| TPS51125RGET | Texas Instruments | — |
| TPS51125RGET.A | Texas Instruments | — |
| TPS51125RGET.B | Texas Instruments | — |
Data on this page is extracted from publicly available manufacturer datasheets using automated tools including AI. It may contain errors or omissions. Always verify specifications against the official manufacturer datasheet before making design or purchasing decisions. See our Terms of Service. Rights holders can submit a takedown request.
Get structured datasheet data via API
Get started free