SGS Thomson Microelectronics L6926D Datasheet

HIGH EFFICIENCY MONOLITHIC SYNCHRONOUS

■ 2V TO 5.5V BATTERY INPUT RANGE

■ HIGH EFFICIENCY: UP TO 95%

■ INTERNAL SYNCHRONOUS SWITCH

■ NO EXTERNAL SCHOTTKY REQUIRED

■ EXTREMELY LOW QUIESCENT CURRENT

■ 1µA MAX SHUTDOWN SUPPLY CURRENT

■ 800mA MAX OUTPUT CURRENT

■

ADJUSTABL E OUTPUT VOLTAGE FROM 0.6V

■ LOW DROP-OUT OPERA TION: UP TO100%

DUTY CYCLE

■ SELECTABLE LOW NOISE/LOW

CONSUMPTION MODE AT LIGHT LOAD

■ POWER GOOD SIGNAL

■ ±1% OUTPUT VOLTAGE ACCURACY

■ CURRENT-MODE CONTROL

■ 600kHz SWITCHING FREQUENCY

■ EXTERNALLY SYNCHRONIZABLE FROM

500kHz TO 1.4MHz

■ OVP

■ SHORT CIRCUIT PROTECTION

APPLICATIONS

■ BATTERY-POWERED EQUIPMENTS

■ PORTABLE INSTRUMENTS

■ CELLULAR PHONES

■ PDAs AND HAND HELD TERMINALS

■ DSC

L6926D

STEP DOWN REGULATOR

MSOP8

ORDERING NUMBERS: L6926D

L6926D013TR (Tape & Reel)

■ GPS

DESCRIPTION

The device is dc-dc monolithic regulator specifically
designed to provide extremely high efficiency.
L6926D supply voltage can be as low as 2V allowing
its use in singl e Li-ion c ell supplied applications . Out­put voltage can be selected by an external divider
down to 0.6V. Duty Cycle can saturate to 100% al­lowing low drop-out operation. The device is based
on a 600kHz fixed-fr equency, current mode -arc hitec­ture. Low Consumption Mode operation can be se­lected at light load conditions, allowing switching
losses to be reduced. L6926D is externally synchro­nizable with a clock which makes it useful in noise­sensitive applications. Other features like Power­good, Overvoltage protection, Shortcircuit protection
and Thermal Shutdown (150°C) are also present.

APPLICATION TEST CIRCUIT

May 2003

V

=2V to 5.5V

IN

C1

10µF

6.3V

SYNC LX

D01IN1305

7

V

CC

RUN

6
1

24

COMP GND

C2

220pF

5

8

3

L 6.8µH

PGOOD

VFB

R3

500K

R2

200K

R1

100K

V

=1.8V

OUT

C4

10µF

6.3V

1/8

L6926D

ABSOLUTE MAXIMUM RATINGS

Symbol Parameter Value Unit

V

6

V

5

V

1

V

3

V

2

Ptot Power dissipation at Tamb=70°C0.45W

Tj Junction operating temperature range -40 to 150 °C

Tstg Storage temperature range -65 to 150 °C

LX Pin Maximum Withstanding Voltage Range Test Condition: CDF-

Other pins ±2000 V

PIN CONNECTION

Input voltage -0.3 to 6 V
Output switching voltage -1 to V
Shutdown -0.3 to V
Feedback voltage -0.3 to V

Analog input voltage -0.3 to V

CC

CC
CC
CC

±1000 V
AEC-Q100-002- “Human Body Model” Acceptance Criteria:
“Normal Performance’

V
V
V
V

RUN

COMP

VFB

GND

1
2
3
4LX

D01IN1239AMOD

PGOOD8
SYNC

7

V

6
5

CC

THERMAL DATA

Symbol Parameter Value Unit

R

th j-amb

Thermal Resistance Junction to Ambient 180 °C/W

PIN FUNCTIONS

N Name Description

1 RUN Shutdown input. When connected to a low level (lower than 0.4V) the device stops working.

When high (higher than 1.3V) the device is enabled.

2 COMP Error amplifier output. A compensation network has to be connected to this pin. Usually a

220pF capacitor is enough to guarantee the loop stability.

3 VFB Error amplifier inverting input. The output voltage can be adjusted from 0.6V up to the input

4 GND Ground.
5 LX Switch output node. This pin is internally connected to the drain of the internal switches.
6 VCC Input voltage. The start up input voltage is 2.2V (typ) while the operating input voltage range is

7 SYNC Operating mode selector input. When high (higher than 1.3V) the Low Consumption Mode is

8 PGOOD Power good comparator output. It is an open drain output. A pull-up resistor should be

voltage by connecting this pin to an external resistor divider.

from 2V to 5.5V. An internal UVLO circuit realizes a 100mV (typ.) hysteresis.

selected. When low (lower than 0.5V) the Low Noise Mode is selected. If connected with an
appropriate external synchronization signal (from 500KHz up to 1.4MHz) the internal
synchronization circuit is activated and the device works at the same switching frequency.

connected between PGOOD and VOUT (or VCC depending on the requirements). The pin is
forced low when the output voltage is lower than 90% of the regulated output voltage and goes
high when the output voltage is greater than 90% of the regulated output voltage. If not used the
pin can be left floating.

2/8

L6926D

ELECTRICAL CHARACTERISTICS

(Tj = 25°C, VCC = 3.6V unless otherwise specified)

Symbol Parameter Test Condition Min Typ Max Unit

V

V

cc ON

V

cc OFF

V

cc hys

R
R
I

V

f

f

sync

cc

p
n

lim

out

osc

Operating input voltage After Turn on 2 5.5 V
Turn On threshold 2.2 V
Turn Off threshold 2 V
Hysteresis 100 mV
High side Ron V
Low side Ron V

= 3.6V, I

cc

= 3.6V, I

cc

=100mA 240 mΩ

lx

=100mA 215 mΩ

lx

Peak current limit Vcc = 3.6V 1.2 A
Valley current limit V
Output voltage range V

= 3.6V 1.4 A

cc

fb

Vcc V
Oscillator frequency 600 KHz
Sync mode clock (*) 500 1400 KHz

DC CHARACTERISTICS

I

q

Quiescent current (low noise
mode)

Quiescent current (low
cunsumption mode)

I

sh

I

lx

Shutdown current RUN to GND, V
LX leakage current (*) RUN to GND, V

V

= 0V , no load, VFB >

sync

0.6V
V

= Vcc, no load, VFB

sync

> 0.6V

V

= 5.5V

cc

RUN to GND, V
V

= 5.5V

cc

230 µA

25 µA

= 5.5V 0.2 µ A

cc
LX

LX

= 5.5V,

= 0V,

1 µA

1 µA

ERROR AMPLIFIER CHARACTERISTICS

V

fb

I

fb

Voltage feedback 0.593 0.6 0.607 V
Feedback input current (*) VFB = 0.6V 25 nA

RUN

V

V

run_H
run_L

I

run

RUN threshold high 1.3 V
RUN threshold low 0.4 V
RUN input current (*) 25 nA

SYNC/MODE FUNCTION

V

sync_H

V

sync_L

Sync mode threshold high 1.3 V
Sync mode threshold low 0.5 V

PGOOD SECTION

V

PGOOD

∆V

PGOOD

V

Pgood(low)

I

LK-PGOOD

Power Good Threshold V
Power Good Hysteresis V
Power Good Low Voltage Run to GND 0.4 V
Power Good Leakage Current

OUT
OUT

V

PGOOD

= V
= V

fb
fb

90 %Vout

4%Vout

= 3.6V 50 nA

(*)

PROTECTIONS

HOVP Hard overvoltage threshold V

(*) Guarant eed by design

OUT

= V

fb

10 %Vout

3/8