ST ST8R00 User Manual

ST8R00

Micropower 1 A synchronous step-up DC-DC converter

Features

■Output voltage adjustable from 6 V to 12 V

■Output voltage accuracy: ± 2%

■ Output current up to 1 A
■ Low ripple voltage: 5 mV (typ.)
■	Synchronous rectification
■ High 90% efficiency: VO = 9 V (typ.)
■	Few external components	DFN8 4 x 4 mm

■Thermal shutdown protection

■Very small DFN8 (4 x 4 mm) package

Description

The ST8R00 is a synchronous PWM step-up DCDC converter. The device is able to provide an output voltage in the range of 6 to 12 V with an input voltage from 4 to 6 V. The high switching frequency (1.7 MHz) permits the use of tiny surface-mount components. In addition to the resistor divider to set the output voltage value, only an inductor and two capacitors are required. Moreover, a low output ripple is guaranteed by the current mode PWM topology and by the use of low ESR SMD ceramic capacitors. The device is available in a very small DFN8 (4 x 4 mm) package.

Table 1. Device summary

Part number	Order code	Output voltage
ST8R00	ST8R00WPUR	ADJ
February 2012	Doc ID 13449 Rev 2	1/18
		www.st.com

Contents	ST8R00

Contents

1	Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 3
2	Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	. 4
3	Typical application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	5
4	Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	6
5	Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	7
6	Typical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	8
7	Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	13
8	Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .	17

2/18	Doc ID 13449 Rev 2

ST8R00	Block diagram

1 Block diagram

Figure 1. Schematic diagram

		LX
	Thermal
		OUT
INH	Inhibit	PGND
		PWM Control
IN		FB
	VREF
	PGND	GND

Doc ID 13449 Rev 2

3/18

Pin configuration	ST8R00

2 Pin configuration

Figure 2. Pin connections (top view)

Table 2.	Pin description
Pin n°		Symbol	Name and function
1		LX	Switching output
2		PGND	Power ground
3		GND	Analog ground
4		IN	Power input for analog circuit
5		FB	Feedback
			Inhibit. Connecting the pin to a voltage higher than 2 V = device ON.
6		INH	Connecting the pin to a voltage lower than 0.8 V = device OFF,
			resulting in no current flow to the load
7		HV	Trimming (floating or connected to GND)
8		OUT	Output voltage
EXP pad		GND	Exposed pad. Must be connected to GND

4/18	Doc ID 13449 Rev 2

ST8R00	Typical application circuit

3 Typical application circuit

Figure 3. Application circuit

VI	L=4.7µH
IN	LX		VO
	OUT
INH		R1
ST8R00 FB
CI=10µF		R2	C =10µF
GND	PGND		O

Doc ID 13449 Rev 2

5/18

Maximum ratings										ST8R00
4	Maximum ratings
Table 3.	Absolute maximum ratings
Symbol		Parameter				Value				Unit
VO		Output voltage				16				V
VI		Input voltage				6				V
VINH		Inhibit voltage				6				V
VLX		LX pin voltage				16				V
ILX		LX pin output current		Internally limited
TSTG		Storage temperature range				-50 to 150				°C
TOP		Operating junction temperature range				-25 to 125				°C
Table 4.	Thermal Data
Symbol		Parameter				Value				Unit
RthJC		Thermal resistance junction-case				10				°C/W
RthJA		Thermal resistance junction-ambient				50				°C/W
Table 5.	ESD Performance
Symbol		Parameter	Test conditions				Value			Unit
ESD	ESD protection voltage		HBM				4			KV
ESD	ESD protection voltage		MM				500			V

6/18	Doc ID 13449 Rev 2