ST L6933H1.2 User Manual

High performance 2A ULDO linear regulator with Soft Start

Features

■ 2 V to 14 V input voltage range

■ 200 mΩ r

■ 200 µA quiescent current at any load

■ Excellent load and line regulation

■ Adjustable from 1.2 V to 5 V

■ 1 % voltage regulation accuracy

■ Power Good output

■ MLCC capacitors filter supported

■ Adjustable Soft Start

■ Short circuit protection

■ Thermal shut down

■ HSOP8 package

Applications

■ Motherboards, mobile PC

■ Hand-held instruments

■ PCMCIA Cards

■ Processors I/O

■ Chipset and RAM supply

Figure 1. Typical operating circuit

DS(on)

max

L6933H1.2

HSOP8

Description

The L6933H1.2 ultra low drop output linear
regulator operates from 2 V to 14 V and is able to
support output current up to 2 A. Designed with
an internal 50 mΩ N-channel MOSFET, it can be
used for on board DC-DC conversions saving in
real estate, list of components, low noise
generation and power dissipation. L6933H1.2 is
available as adjustable version from 1.2 V to 5 V
with a voltage regulation accuracy of 1 %.
A Soft Start function allows the device to smoothly
increase the Output Voltage at the start-up,
avoiding overshoot. Inhibit function is provided.
The upper current limit is fixed at 2.5 A to control
the current in short circuit condition within ± 8 %.
The current is sensed in the power MOS in order
to limit the power dissipation.
The device is also provided with a thermal shut
down that limits the internal temperature at
150 °C with a histeresys of 20 °C.

Table 1. Device summary

Order codes Package Packaging

L6933H1.2 HSOP8 Tube

L6933H1.2TR HSOP8 Tape and reel

November 2007 Rev 3 1/12

www.st.com

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Contents L6933H1.2

Contents

1 Pin settings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.1 Pin connection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

1.2 Pin description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1 Absolute maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.2 Thermal data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

3 Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

4 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

5 Typical electrical performance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

6 Soft-Start . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

7 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

7.1 Application circuit . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

7.2 Demoboard layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

7.3 Component part list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

8 Components selection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

8.1 Input capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

8.2 Output capacitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

9 Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

10 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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L6933H1.2 Pin settings

1 Pin settings

1.1 Pin connection

Figure 2. Pin connection (top view)

1.2 Pin description

Table 2. Pin description

Pin N° Name Description

The soft-start time is programmed connecting an external capacitor from this
pin and GND. The internal current generator forces a current of 5 µA through

SS/INH 1

VIN 2

ADJ 3

VOUT 4

PGOOD 5

NC 7, 8 Not connected

GND 6 Ground pins internally connected

the capacitor. In steady state regulation, the voltage at this pin will be about 8 V.
This pin is also used to inhibit the device: when the voltage at this pin is lower
than the 0.5 V, the device is disabled.

Supply voltage. This pin is connected to the drain of the internal N-mos.
Connect this pin to a capacitor larger than 10 µF.

Connecting this pin to a voltage divider it is possible to program the output
voltage between 1.2 V and 5 V.

Regulated output voltage. This pin is connected to the source of the internal N­mos. Connect this pin to a capacitor of 10 µF.

Power good output. The pin is open drain and detects the output voltage. It is
forced low if the output voltage is lower than 90 % the programmed voltage.

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Maximum ratings L6933H1.2

2 Maximum ratings

2.1 Absolute maximum ratings

Table 3. Absolute maximum ratings

Symbol Parameter Value Unit

V

IN

2.2 Thermal data

Table 4. Thermal data

Symbol Parameter Value Unit

R

thJA

T

MAX

T

STG

1. Package mounted on board

VIN and PGood 14.5 V

SS/INH, OUT and ADJ -0.3 to (Vin +0.3) V

Maximum thermal resistance junction-ambient

Maximum junction temperature 150 °C

Storage temperature range -65 to 150 °C

34

(1)

°C/W

3 Block diagram

Figure 3. Block diagram

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