LM5166DRCT
Synchronous Buck ConverterThe LM5166DRCT is a synchronous buck converter from Texas Instruments. View the full LM5166DRCT datasheet below including key specifications, electrical characteristics, absolute maximum ratings.
LM5166DRCT shares its datasheet with LM5166, whose page lists every part number it covers.
Official LM5166DRCT datasheet (PDF) — the source this page was extracted from.
Manufacturer
Texas InstrumentsCategory
Switching Regulators (Buck)LM5166DRCT Key Specifications
| Parameter | Value |
|---|---|
| Input voltage range | 3–65 V |
| Output current | up to 500 mA (peak current limit programmable for 500 mA, 300 mA, or 200 mA loads) |
| No-load quiescent current | 9.7 μA |
| Reference voltage | 1.223 V ±1.2% |
| Integrated high-side PFET | 1 Ω; synchronous NFET: 0.5 Ω |
| Soft start | 900 μs internal, or externally adjustable |
| Switching frequency | up to 600 kHz |
LM5166DRCT Overview
Part: LM5166Y (LM5166YDRCR) — Texas Instruments
Type: Synchronous Buck Converter (3.3 V fixed output version)
Description: 3–65 V input, 500 mA synchronous buck converter with integrated high-side and low-side FETs, 9.7 μA no-load quiescent current, and a fixed 3.3 V output (LM5166Y).
Operating Conditions:
- Supply voltage (VIN): 3–65 V
- Operating junction temperature: -40 to 150 °C
- Output current: 0–500 mA
- Switching frequency up to 600 kHz
Absolute Maximum Ratings:
- Max input voltage (VIN, EN to GND): 68 V
- SW to GND: -0.7 V to VIN + 0.3 V (-3 V for 20 ns transient)
- PGOOD, VOUT to GND: 16 V
- Max junction temperature: 150 °C
- Storage temperature: -55 to 150 °C
Key Specs:
- Input voltage range: 3–65 V
- Output current: up to 500 mA (peak current limit programmable for 500 mA, 300 mA, or 200 mA loads)
- No-load quiescent current: 9.7 μA
- Reference voltage: 1.223 V ±1.2%
- Integrated high-side PFET: 1 Ω; synchronous NFET: 0.5 Ω
- Soft start: 900 μs internal, or externally adjustable
- Switching frequency: up to 600 kHz
Features:
- Selectable PFM or constant on-time (COT) mode operation
- Supports 100% duty cycle for low dropout
- No loop compensation or bootstrap components required
- Diode emulation and pulse skipping for high light-load efficiency
- Precision enable and input UVLO with hysteresis
- Open-drain power good indicator
- Thermal shutdown protection with hysteresis
- Meets EN55022 / CISPR 22 EMI standards
- Pin-to-pin compatible with the LM5165
Applications:
- Factory and building automation
- Automotive and battery-powered applications
- High voltage LDO replacement
- Low power bias supplies
Package:
- VSON-10 (3 mm × 3 mm, 0.5 mm pin pitch)
LM5166DRCT Features
- 1 · Wide Input Voltage Range of 3 V to 65 V
- 9.7-μA No-Load Quiescent Current
- -40°C to 150°C Junction Temperature Range
- Fixed (3.3-V, 5-V) or Adjustable VOUT Options
- Meets EN55022 / CISPR 22 EMI Standards
- Integrated 1Ω PFET Buck Switch
- -Supports 100% Duty Cycle for Low Dropout
- Integrated 0.5Ω NFET Synchronous Rectifier
- -Eliminates External Schottky Diode
- Programmable Peak Current Limit Supports:
- -500-mA, 300-mA, or 200-mA Loads
- Selectable PFM or COT Mode Operation
- 1.223-V ±1.2% Internal Voltage Reference
- Switching Frequency up to 600 kHz
- 900-μs Internal or Externally-Adjustable Soft Start
- Diode Emulation and Pulse Skipping for UltraHigh Light-Load Efficiency
- No Loop Compensation or Bootstrap Components
- Precision Enable and Input UVLO With Hysteresis
- Open-Drain Power Good Indicator
- Thermal Shutdown Protection With Hysteresis
- Pin-to-Pin Compatible With the LM5165
- 10-Pin, 3-mm × 3-mm VSON Package
- Create a Custom Regulator Design Using WEBENCH ® Power Designer
LM5166DRCT Applications
- Factory and Building Automation
- Automotive and Battery-Powered Applications
- High Voltage LDO Replacement
- Low Power Bias Supplies
LM5166DRCT Pin Configuration
| PIN - NO. | PIN - NAME | I/O (1) | DESCRIPTION |
|---|---|---|---|
| 1 | SW | P | Switching node that is internally connected to the drain of the PFET buck switch (high side) and the drain of the NFET synchronous rectifier (low side). Connect to the buck inductor. |
| 2 | VIN | P | Regulator supply input pin to high-side power MOSFET and internal bias rail LDO. Connect to input supply and input filter capacitor C IN . The path from the VIN pin to the input capacitor must be as short as possible. |
| 3 | ILIM | I | Programming pin for current limit. Connecting the appropriate resistance from the ILIM pin to GND selects one of the three current limit options. The available current limit options are detailed in Table 3. |
| 4 | SS | I | Programming pin for the soft-start delay. If a 100-k Ω resistor is connected from the SS pin to GND, the internal soft-start circuit is disabled and the FB comparator reference steps immediately from zero to full value when the regulator is enabled by the EN input. If the SS pin is left open, the internal soft-start circuit ramps the FB reference from zero to full value in 900 μs. If a capacitor is connected from the SS pin to GND, the soft-start time can be set longer than 900 μs. |
| 5 | RT | I | Mode select and on-time programming pin for Constant On-Time control. Connect a resistor from the RT pin to GND to program the on-time and hence switching frequency. Short RT to GND to select PFM (pulse frequency modulation) operation. |
| 6 | PGOOD | O | Power Good output flag pin. PGOOD is connected to the drain of an NFET that holds the pin low when either FB or VOUT is not in regulation. Use a 10-k Ω to 100-k Ω pullup resistor to system voltage rail or VOUT (no higher than 12 V). |
| 7 | EN | I | Input pin of the precision enable / UVLO comparator. The regulator is enabled when the EN pin voltage is greater than 1.22 V. |
| 8 | VOUT or FB | I | Feedback input to the voltage regulation loop for the LM5166 Adjustable Output version, or a VOUT pin connects the internal feedback resistor divider to the regulator output voltage for the fixed 3.3-V or 5-V options. The FB pin connects the internal feedback comparator to an external resistor divider for the adjustable voltage option, and the reference for the FB pin comparator is 1.223 V. |
| 9 | HYS | O | Drain of internal NFET that is turned off when the EN input is greater than the EN pin threshold. External resistors from HYS to EN and GND program the input UVLO threshold and hysteresis. |
| 10 | GND | G | Regulator ground return. |
| - | PAD | P | Connect to GND pin and system ground on PCB. Path to C IN must be as short as possible. |
LM5166DRCT Electrical Characteristics
Typical values correspond to TJ = 25°C. Minimum and maximum limits are based on TJ = -40°C to +125°C. VIN = 12 V (unless otherwise noted). (1)(2)
| PARAMETER | TEST CONDITIONS | MIN | TYP | MAX | UNIT | |
|---|---|---|---|---|---|---|
| I Q-SD | VIN DC supply current, shutdown | V EN = 0 V, T J = 25°C | 4 | 6 | μA | |
| I Q-SLEEP | VIN DC supply current, no load | V FB = 1.5 V, T J = 25°C | 9.7 | 15 | μA | |
| I Q-SLEEP- VINMAX | VIN DC supply current, no load | V FB = 1.5 V, V VIN = 65 V, T J = 25°C | 10 | 15 | μA | |
| I Q-ACTIVE-PFM | VIN DC supply current, active | PFM mode, R RT = 0 Ω , R SS = 100 k Ω | 205 | μA | ||
| I Q-ACTIVE-COT | VIN DC supply current, active | COT mode, R RT = R SS = 100 k Ω | 320 | μA | ||
| POWER SWITCHES | POWER SWITCHES | POWER SWITCHES | POWER SWITCHES | POWER SWITCHES | POWER SWITCHES | POWER SWITCHES |
| R DSON1 | High-side MOSFET R DS(on) | I SW = -100 mA | 0.93 | Ω | ||
| R DSON2 | Low-side MOSFET R DS(on) | I SW = 100 mA | 0.48 | Ω | ||
| CURRENT LIMITING | CURRENT LIMITING | CURRENT LIMITING | CURRENT LIMITING | CURRENT LIMITING | CURRENT LIMITING | CURRENT LIMITING |
| I HS_LIM1 | High-side peak current limit threshold | 1125 | 1250 | 1375 | ||
| I HS_LIM2 | See Table 3 | 675 | 750 | 825 | mA | |
| I HS_LIM3 | 440 | 500 | 560 | |||
| I LS_LIM1 | Low-side valley current limit | 415 | mA | |||
| I LS_LIM2 | threshold | See Table 3 | 315 | |||
| REGULATION COMPARATOR | REGULATION COMPARATOR | REGULATION COMPARATOR | REGULATION COMPARATOR | REGULATION COMPARATOR | REGULATION COMPARATOR | REGULATION COMPARATOR |
| V VOUT5 | VOUT 5-V DC setpoint | LM5166X | 4.9 | 5.0 | 5.1 | V |
| V VOUT3.3 | VOUT 3.3-V DC setpoint | LM5166Y V VOUT = 5 V, LM5166X | 3.23 | 3.3 7 | 3.37 | V |
| I VOUT | VOUT pin input current | V VOUT = 3.3 V, LM5166Y | 3.8 | μA | ||
| V FB1 | Lower FB regulation threshold (PFM and COT) | Adjustable VOUT version | 1.208 | 1.223 | 1.238 | V |
| V FB2 | Upper FB regulation threshold (PFM) | 1.218 | 1.233 | 1.248 | V | |
| I FB | FB pin input bias current | V FB = 1 V | 25 | nA | ||
| FB HYS-PFM | FB comparator PFM hysteresis | PFM mode | 10 | mV | ||
| FB HYS-COT | FB comparator dropout hysteresis | COT mode | 4 | mV | ||
| FB LINE-REG | FB threshold variation over line | V VIN = 3 V to 65 V | 0.005 | %/V | ||
| VOUT LINE-REG | VOUT threshold variation over line | LM5166X, V VIN = 6 V to 65 V LM5166Y, V VIN = 4.5 V to 65 V | 0.005 | %/V | ||
| POWER GOOD | POWER GOOD | POWER GOOD | POWER GOOD | POWER GOOD | POWER GOOD | POWER GOOD |
| UVT RISING | PGOOD comparator | V FB rising relative to V FB1 threshold | 94% | |||
| UVT FALLING | V FB falling relative to V FB1 threshold | 87% | ||||
| R PGOOD | PGOOD on-resistance | V FB = 1 V | 80 | 200 | Ω | |
| V INMIN-PGOOD | Minimum required VIN for valid PGOOD | V VIN falling I PGOOD = 0.1 mA, V PGOOD < 0.5 V | 1.2 | 1.65 | V | |
| I PGOOD | PGOOD off-state leakage | V FB = 1.2 V, V PGOOD = 5.5 V | 10 | 100 | nA | |
| ENABLE / UVLO | ENABLE / UVLO | ENABLE / UVLO | ENABLE / UVLO | ENABLE / UVLO | ENABLE / UVLO | ENABLE / UVLO |
| V IN-ON | Turnon threshold | V VIN rising | 2.60 | 2.75 | 2.95 | V |
| V IN-OFF | Turnoff threshold | V VIN falling | 2.35 | 2.45 | 2.60 | V |
| V EN-ON | EN turnon threshold | V EN rising | 1.163 | 1.22 | 1.276 | V |
| V EN-OFF | EN turnoff threshold | V EN falling | 1.109 | 1.144 | 1.178 | V |
LM5166DRCT Absolute Maximum Ratings
Over the recommended operating junction temperature range of -40°C to 150°C (unless otherwise noted). (1)(2)
| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| VIN, EN to GND | -0.3 | 68 | V | |
| SW to GND | -0.7 | V VIN + 0.3 | V | |
| SW to GND | 20-ns transient | -3 | V | |
| PGOOD, VOUT (3) to GND | -0.3 | 16 | V | |
| HYS to GND | -0.3 | 7 | V | |
| ILIM, SS, RT, FB (4) to GND | -0.3 | 3.6 | V | |
| Maximum junction temperature, T J | -40 | 150 | °C | |
| Storage temperature, T stg | -55 | 150 | °C |
LM5166DRCT Recommended Operating Conditions
Over the recommended operating junction temperature range of -40°C to 150°C (unless otherwise noted). (1)
| MIN | NOM | MAX | UNIT | ||
|---|---|---|---|---|---|
| Input voltages | VIN | 3 | 65 | V | |
| Input voltages | EN | -0.3 | 65 | V | |
| Input voltages | PGOOD | -0.3 | 12 | V | |
| Input voltages | HYS | -0.3 | 5.5 | V | |
| Output current | I OUT | 0 | 500 | mA | |
| Temperature | Operating junction temperature | -40 | 150 | °C |
LM5166DRCT Thermal Information
| THERMAL METRIC (1) | LM5166 DRC (VSON) - 10 PINS | UNIT | |
|---|---|---|---|
| R θ JA | Junction-to-ambient thermal resistance | 49.1 | °C/W |
| R θ JC(top) | Junction-to-case (top) thermal resistance | 57.2 | °C/W |
| R θ JB | Junction-to-board thermal resistance | 26.6 | °C/W |
| ψ JT | Junction-to-top characterization parameter | 0.8 | °C/W |
| ψ JB | Junction-to-board characterization parameter | 23.8 | °C/W |
| R θ JC(bot) | Junction-to-case (bottom) thermal resistance | 4.8 | °C/W |
LM5166DRCT Typical Application
The LM5166 only requires a few external components to convert from a wide range of supply voltages to a fixed output voltage. To expedite and streamline the process of designing a LM5166-based converter, a comprehensive LM5166 Quickstart Calculator is available for download to assist the designer with component selection for a given application. WEBENCH ® online software is also available to generate complete designs, leveraging iterative design procedures and access to comprehensive component databases. The following sections discuss the design procedure for both COT and PFM converters using specific circuit design examples.
The LM5166 integrates several optional features to meet system design requirements, including precision enable, UVLO, programmable soft start, programmable switching frequency in COT mode, adjustable current limit, and PGOOD indicator. Each application incorporates these features as needed for a more comprehensive design. The application circuits detailed below show LM5166 configuration options suitable for several application use cases. Please see the LM5166EVM-C50A and LM5166EVM-C33A EVM user's guides for more detail.
Other Switching Regulators (Buck)
- TPS54302 – Texas Instruments, Synchronous Step-Down Converter
- MAX20730 – Analog Devices, Synchronous Switching Regulator
- TLV62568 – Texas Instruments, Synchronous Buck Converter
- LM2596 – onsemi, Step-Down Voltage Regulator
- TPS562200 – Texas Instruments, Synchronous Buck Converter
- AP63357DV-7 – Diodes Incorporated, Synchronous Buck Converter
- MP2344GJ-Z – Monolithic Power Systems, Synchronous Step-Down Converter
- MP1584EN – Monolithic Power Systems, Buck Converter
All Switching Regulators (Buck) datasheetsAll Texas Instruments datasheets (2,442)
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