LM5166YDRCR

Synchronous Buck Converter

The LM5166YDRCR is a synchronous buck converter from Texas Instruments. View the full LM5166YDRCR datasheet below including key specifications, electrical characteristics, absolute maximum ratings.

Manufacturer

Texas Instruments

Key Specifications

Parameter	Value
Output Current	500 mA
Output Voltage	Fixed 3.3 V, Fixed 5 V, or Adjustable
Input Voltage Range	3 V to 65 V
No-Load Quiescent Current	9.7 µA
Operating Junction Temperature Range	-40°C to 150\u0

Overview

Part: LM5166 — Texas Instruments

Type: Synchronous Buck Converter

Description: 3-V to 65-V input, 500-mA synchronous buck converter with ultra-low 9.7-μA no-load quiescent current, integrated high-side PFET and low-side NFET, and fixed (3.3-V, 5-V) or adjustable output options.

Operating Conditions:

Supply voltage: 3 V to 65 V
Operating temperature: -40°C to 150°C (Junction)
Output voltage: Fixed (3.3-V, 5-V) or Adjustable
Switching frequency: up to 600 kHz

Absolute Maximum Ratings:

Max supply voltage: 65 V
Max continuous current: 500 mA
Max junction temperature: 150 °C

Key Specs:

No-load quiescent current: 9.7-μA
Integrated PFET Buck Switch R_DS(ON): 1Ω
Integrated NFET Synchronous Rectifier R_DS(ON): 0.5Ω
Internal Voltage Reference: 1.223-V ±1.2%
Programmable Peak Current Limit: 500-mA, 300-mA, or 200-mA
Soft Start: 900-μs internal
FB maximum current: 25 nA

Features:

Wide Input Voltage Range of 3 V to 65 V
9.7-μA No-Load Quiescent Current
Integrated 1Ω PFET Buck Switch and 0.5Ω NFET Synchronous Rectifier
Supports 100% Duty Cycle for Low Dropout
Selectable PFM or COT Mode Operation
Open-Drain Power Good Indicator

Applications:

Factory and Building Automation
Automotive and Battery-Powered Applications
High Voltage LDO Replacement
Low Power Bias Supplies

Package:

VSON (10-Pin, 3-mm × 3-mm)

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

Applications

Factory and Building Automation
Automotive and Battery-Powered Applications
High Voltage LDO Replacement
Low Power Bias Supplies

Pin Configuration

(1) P = Power, G = Ground, I = Input, O = Output.

PIN	PIN	I/O (1)	DESCRIPTION
NO.	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.

LM5166 Adjustable Output DRC Package 10-Pin VSON Top View

(1) P = Power, G = Ground, I = Input, O = Output.

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	See Table 3	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

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

Recommended Operating Conditions

Over the recommended operating junction temperature range of -40°C to 150°C (unless otherwise noted). (1)

		MIN	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

Thermal Information

	THERMAL METRIC (1)	LM5166 DRC (VSON)	UNIT
		10 PINS
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

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.

Related Variants

The following components are covered by the same datasheet.

Part Number	Manufacturer	Package
LM5166	Texas Instruments	—
LM5166DRCR	Texas Instruments	—
LM5166DRCR.A	Texas Instruments	—
LM5166DRCT	Texas Instruments	—
LM5166DRCT.A	Texas Instruments	—
LM5166X	Texas Instruments	VSON (10-Pin)
LM5166XDRCR	Texas Instruments	—
LM5166XDRCR.A	Texas Instruments	—
LM5166XDRCT	Texas Instruments	—
LM5166XDRCT.A	Texas Instruments	—
LM5166Y	Texas Instruments	VSON (10-Pin)
LM5166YDRCR.A	Texas Instruments	—
LM5166YDRCT	Texas Instruments	—
LM5166YDRCT.A	Texas Instruments	—

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