ST1S14

Step-Down Switching Regulator

The ST1S14 is a step-down switching regulator from STMicroelectronics. View the full ST1S14 datasheet below including key specifications, electrical characteristics, absolute maximum ratings.

Manufacturer

STMicroelectronics

Key Specifications

Parameter	Value
Output Current	3A
Switching Frequency	850kHz
Function	Step-Down
Mounting Type	Surface Mount
Number of Outputs	1
Operating Temperature	-40°C ~ 125°C (TJ)
Output Configuration	Positive
Output Type	Adjustable
Package / Case	8-SOIC (0.154", 3.90mm Width) Exposed Pad
Supplier Device Package	8-HSOP
Supplier Device Package	8-HSOP
Supplier Device Package	8-HSOP
Synchronous Rectifier	No
Topology	Buck
Input Voltage (Max)	48V
Input Voltage (Min)	5.5V
Output Voltage (Max)	43.2V
Output Voltage	1.22V

Overview

Part: ST1S14 — STMicroelectronics

Type: Step-down switching regulator

Description: The ST1S14 is a step-down monolithic power switching regulator capable of delivering up to 3 A DC current to the load, operating from a 5.5 V to 48 V input voltage, with an 850 kHz internally fixed switching frequency.

Operating Conditions:

Supply voltage: 5.5–48 V
Operating junction temperature: -40 to 125 °C
Output voltage: from 1.22 V

Absolute Maximum Ratings:

Max supply voltage: 52 V
Max switching node voltage: (V IN +0.3) V
Max junction temperature: 150 °C
Max storage temperature: 150 °C

Key Specs:

MOSFET on resistance (R DS(on)): 0.2 Ω typ. (I SW =1 A)
Maximum limiting current (I SW): 4.5 A typ. (3.7 A min, 5.2 A max)
Switching frequency (f SW): 850 kHz typ. (600 kHz min, 1000 kHz max)
Voltage feedback (V FB): 1.22 V typ. (1.196 V min, 1.245 V max) (I LOAD =10 mA to 3 A)
Quiescent current (I q): 1.3 mA typ. (2 mA max) (V FB =2 V)
Standby quiescent current (I qst-by): 16 μA typ. (34 μA max)
Thermal shutdown temperature (T SHDWN): 150 °C typ. (140 °C min, 160 °C max)
Thermal resistance junction-ambient (R th JA): 40 °C/W

Features:

3 A DC output current
Internal soft-start
Power good open collector output
Current mode architecture
Embedded compensation network
Zero load current operation
Internal current limiting
Inhibit for zero current consumption
Thermal shutdown

Applications:

Factory automation
Printers
DC-DC modules
High current LED drivers

Package:

HSOP8 (with exposed frame)

Features

3 A DC output current
Operating input voltage from 5.5 V to 48 V
850 kHz internally fixed switching frequency
Internal soft-start
Power good open collector output
Current mode architecture
Embedded compensation network
Zero load current operation
Internal current limiting
Inhibit for zero current consumption
2 mA maximum quiescent current over temperature range
250 m Ω typ. R DS(on)
Thermal shutdown

Applications

Factory automation
Printers
DC-DC modules
High current LED drivers

Pin Configuration

Table 1. Pin description

N	Pin	Description
1	BOOT	Bootstrap capacitor for N-channel gate driver. Connects 100 nF low ESR capacitor from BOOT pin to SW
2	PG	Power good
3	EN1	Enable pin active low
4	FB	Feedback voltage
5	EN2	Enable pin active high
6	GND	Ground pin
7	V IN	Input supply pin
8	SW	Switching node
	E.p.	Exposed pad must be connected to GND

Electrical Characteristics

All the population tested at T J = 25 °C, V CC =12 V, V EN1 = 0 V, V EN2 = V CC unless otherwise specified.

The specification is guaranteed from (-40 to +125 °C) T J temperature range by design, characterization, and statistical correlation.

Table 6. Electrical characteristics

Symbol	Parameter	Test condition		Min	Typ	Max	Unit
V IN	Operating input voltage range			5.5		48	V
R DS(on)	MOSFET on resistance	I SW =1 A			0.2	0.4	Ω
I SW	Maximum limiting current			3.7	4.5	5.2	A
t HICCUP	Hiccup time				16		ms
f SW	Switching frequency			600	850	1000	kHz
	Duty cycle		(1)		90		%
T ON MIN	Minimum conduction time of the power element		(1)		90		ns
T OFF MIN	Minimum conduction time of the external diode		(1)	75	90	120	ns
DC characteristics	DC characteristics	DC characteristics	DC characteristics	DC characteristics	DC characteristics	DC characteristics	DC characteristics
V FB	Voltage feedback	I LOAD =0 A		1.202	1.22	1.239	V
V FB	Voltage feedback	I LOAD =10 mA to 3 A		1.196	1.22	1.245	V
I FB	FB biasing current				50		nA
I q	Quiescent current	V FB =2 V			1.3	2	mA
I q	Quiescent current	V FB =2 V, V IN =48 V			1.7	2.4	mA
I qst-by	Standby quiescent current	Device OFF (see Table 2 )			16	34	μ A
PG	Power good threshold	V FB rising edge			0.92* V OUT		V
PG	Power good threshold	V FB falling edge			0.8* V OUT		V
PG	PG output voltage (open collector active)	I SINK =6 mA				0.4	V
Inhibit	Inhibit	Inhibit	Inhibit	Inhibit	Inhibit	Inhibit	Inhibit

Table 6. Electrical characteristics

Table 6. Electrical characteristics (continued)

Symbol	Parameter	Test condition		Min	Typ	Max	Unit
V EN1	Enable 1 levels	Device ON V IN =5.5 V to 48 V				0.5	V
V EN1	Enable 1 levels	Device OFF V IN =5.5 V to 48 V		1.5			V
I EN1	Enable 1 biasing current	V EN1 =5 V		0.7	1.6	3.5	μ A
V EN2	Enable 2 levels	Device ON V IN =5.5 V to 48 V		1.5			V
V EN2	Enable 2 levels	Device OFF V IN =5.5 V to 48 V				0.5	V
I EN2	Enable 2 biasing current	V EN1 =0 V; V EN2 =0 V		-1	-2.4	-4.5	μ A
I EN2	Enable 2 biasing current	V EN1 =0 V; V EN2 =12 V		2.7	5.8	10	μ A
I EN2	Enable 2 biasing current	V EN1 =0 V; V CC =V EN2 =48 V		3.0	6.0	10	μ A
Thermal shutdown	Thermal shutdown	Thermal shutdown	Thermal shutdown	Thermal shutdown	Thermal shutdown	Thermal shutdown	Thermal shutdown
T SHDWN	Thermal shutdown temperature		(1)	140	150	160	° C
T HYS	Thermal shutdown hysteresis		(1)		15		° C

Absolute Maximum Ratings

Table 3. Absolute maximum ratings

Table 3. Absolute maximum ratings

Symbol	Parameter	Value	Unit
V IN	Power supply input voltage	-0.3 to 52	V
V EN1	Enable 1 voltage	-0.3 to 7	V
V EN2	Enable 2 voltage	-0.3 to (V IN +0.3)	V
PG	Power good	-0.3 to (V IN +0.3)	V
BOOT	Bootstrap pin	-0.3 to 55	V
SW	Switching node	-1 to (V IN +0.3)	V
V FB	Feedback voltage	-0.3 to 3	V
T J	Operating junction temperature range	-40 to 150	°C
T STG	Storage temperature range	-65 to 150	°C
T LEAD	Lead temperature (soldering 10 sec.)	260	°C

Thermal Information

Table 4. Thermal data

Symbol	Parameter	Value	Unit
R th JA	Thermal resistance junction-ambient	40	° C/W

Typical Application

Figure 25. Demonstration board application circuit

Table 11. Component list

Reference	Part number	Description	Manufacturer
C2, C3	UMK325BJ106MM-T	10 μ F 50 V (size 1210)	Taiyo Yuden
C6, C6		100 nF 50 V (size 0603)

Reference	Part number	Description	Manufacturer
C7		150 pF 50 V (size 0603)
C8	EKZE500ESS101MHB5D	100 μ F 50 V (size 8 x 11.5 mm)	Nippon Chemicon
C1, C9, C10, C11		Not Mounted
R1		4.7 K Ω (size 0603)
R2		2.7 K Ω (size 0603)
R3		47 K Ω (size 0603)
D1	STPS3L60U	3 A 60 V (size SMB)	ST
L1	744314850	8.5 μ H I SAT =4.5 A, I RMS =4 A (size 7 x 6.9 x 4.8 mm)	Wurth

Figure 26. PCB layout (component side)

Table 11. Component list (continued)

Figure 27. PCB layout (bottom side)

Package Information

In order to meet environmental requirements, ST offers these devices in different grades of ECOPACK packages, depending on their level of environmental compliance. ECOPACK specifications, grade definitions and product status are available at: www.st.com . ECOPACK is an ST trademark.

Figure 51. Package dimensions

Figure 51. Package dimensions

Table 12. HSOP8 mechanical data

Dim.	mm	mm	mm
Dim.	Min.	Typ.	Max.
A			1.75
A1			0.15
A2	1.25
b	0.38		0.51
c	0.17		0.25
D	4.80	4.90	5.00
D1	3.10	3.30	3.50
E	5.80	6.00	6.20
E1	3.80	3.90	4.00
E2	2.20	2.40	2.60
e		1.27
h	0.30		0.50
L	0.45		0.80
k	0 °		8 °

Related Variants

The following components are covered by the same datasheet.

Part Number	Manufacturer	Package
ST1S14PHR	STMicroelectronics	8-SOIC (0.154", 3.90mm Width) Exposed Pad

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