TPS51125
Dual-Synchronous, Step-Down ControllerThe TPS51125 is a dual-synchronous, step-down controller from Texas Instruments. View the full TPS51125 datasheet below including key specifications, electrical characteristics, absolute maximum ratings.
Official TPS51125 datasheet (PDF) — the source this page was extracted from.
Manufacturer
Texas InstrumentsCategory
Dual-Synchronous, Step-Down Controller
TPS51125 Key Specifications
| Parameter | Value |
|---|---|
| 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) |
TPS51125 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)
TPS51125 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)
TPS51125 Applications
- Notebook Computers
- I/O Supplies
- System Power Supplies
TPS51125 Pin Configuration
RGE PACKAGE 24 PINS TOP VIEW
Pin Functions
| PIN | PIN | I/O | DESCRIPTION |
|---|---|---|---|
| NAME | NO. | I/O | DESCRIPTION |
| DRVH1 | 21 | O | High-side N-channel MOSFET driver outputs. LL referenced drivers. |
| DRVH2 | 10 | O | High-side N-channel MOSFET driver outputs. LL referenced drivers. |
| DRVL1 | 19 | O | Low-side N-channel MOSFET driver outputs. GND referenced drivers. |
| DRVL2 | 12 | O | Low-side N-channel MOSFET driver outputs. GND referenced drivers. |
| ENTRIP1 | 1 | 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 R DS(on) sense. Short to ground to shutdown a switcher channel. |
| ENTRIP2 | 6 | 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 R DS(on) sense. Short to ground to shutdown a switcher channel. |
| EN0 | 13 | I/O | Master enable input. Open : LDOs on, and ready to turn on VCLK and switcher channels. 620 k Ω to GND : enable both LDOs, VCLK off and ready to turn on switcher channels. Power consumption is almost the same as the case of VCLK = ON. GND : disable all circuit |
| GND | 15 | - | Ground. |
| LL1 | 20 | I | Switch node connections for high-side drivers, current limit and control circuitry. |
| LL2 | 11 | I | Switch node connections for high-side drivers, current limit and control circuitry. |
| PGOOD | 23 | O | Power Good window comparator output for channel 1 and 2. (Logical AND) |
| SKIPSEL | 14 | I | Selection pin for operation mode: OOA auto skip : Connect to VREG3 or VREG5 Auto skip : Connect to VREF Auto skip : Connect to VREF |
| TONSEL | 4 | I | On-time adjustment pin 365 kHz/460 kHz setting : connect to VREG5 300 kHz/375 kHz setting : connect to VREG3 245 kHz/305 kHz setting : connect to VREF 200 kHz/250 kHz setting : connect to GND |
TPS51125 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 |
TPS51125 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 |
TPS51125 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 |
TPS51125 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 |
TPS51125 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.
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