AIM AT1380A Datasheet

AT1380A

Switching Regulator Controller for LCD Bias

Features

•2.5 to 15 V supply voltage operating range.

•Low current consumption: 6 mA in operation,
1 µA or less in stand-by.

•20 kHz to 1 MHz operation frequency range.

•Provides a fixed output current with minimal
supply voltage fluctuations by using an external
resistor to set the output current.

• Totem-pole output.

• Built-in soft start circuit.

• Built-in timer-latch short circuit detection and
protection circuit (SCP).

Applications

• LCD Displays

• PDAs

• Digital Still Cameras

Block Diagram

General Description

The AT1380A is a single-channel PWM control IC
for DC/DC conversion with soft start function and
short circuit detection. Adjustable soft start is
programmed with an external capacitor on SCP
pin. The AT1380A is ideal for up, down and fly­back conversion.

2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: [phone] WWW: http://www.aimtron.com.tw
Fax: [phone] Email: [e-mail]

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AT1380A

Switching Regulator Controller for LCD Bias

Pin Configuration

Ordering Information

Part number Package Remarks

AT1380A 8-pin Plastic SOP AT1380AS
AT1380A 8-pin TSSOP AT1380AP

Pin Description

Pin No. Symbol I/O Description

1 IN- I Error amplifier inverting input
2 SCP — Soft start and SCP setting capacitor connection
3 VCC — Power supply
4 BR/CTL I Output current setting
5 OUT O Totem-pole type output
6GND—Ground
7 OSC — Capacitor and resistor connection pin for setting the oscillation

frequency

8 FB O Error amplifier output

2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: [phone] WWW: http://www.aimtron.com.tw
Fax: [phone] Email: [e-mail]

2

AT1380A

Switching Regulator Controller for LCD Bias

Absolute Maximum Ratings

(Ta=+250C)

Rated ValueParameter Symbol Condition

Unit

Min. Max.

Power supply voltage V
Output source current I
Output sink current I
Allowable dissipation

Operating temperature T
Storage temperature T

CC

+

O

-

O

P

D

P

D

OP

stg

SOP-8, Ta ≦+25°C

TSSOP-8, Ta ≦+25°C

——15V
——-50mA
——50mA

—570 mW
—430 mW

—-30+85
— -55 +125

0

C

0

C

ESD Classification MIL-STD-883 Class 2

* : When mounted on a 10 cm square double-sided epoxy board

WA R N IN G : Do not exceed these ratings. IC devices can be permanently damaged by stress (voltage,
current, temperature, etc.) in excess of absolute maximum ratings.

Recommended Operating Conditions

(Ta=+250C)

Va lu esParameter Symbol

Min. Typ. Max.

Power supply voltage V
Error amplifier input voltage V
BR/CTL pin input voltage V
Output source current I
Output sink current I
SCP pin capacitance C
Phase compensation capacitance C
Output current setting resistance R

Timing resistance R
Timing capacitance C

Oscillation frequency f
Operating temperature T

O

O

OSC

OP

CC

BR

PE

I

+

-

P

B

T

T

2.5 -- 13.5

-0.2 -- 1.0

-0.2 -- V

CC

-20 -- --

-- -- 40

-- 0.1 --

-- 0.1 --

150 390 5000 Ω

1.0 3.0 10.0

100 270 10000 pF

10 500 1000 kHz

-30 +25 +85 °C

WA R N IN G : Recommended operating conditions are normal operating ranges for the IC device. All
the device’s electrical characteristics are warranted for operation within these ranges. Use IC devices
only within the recommended operating conditions. Operation outside these ranges may adversely
affect the reliability and can result in device failure.

Unit

Ｖ
Ｖ

Ｖ
ｍＡ
ｍＡ
μＦ
μＦ

ｋΩ

2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: [phone] WWW: http://www.aimtron.com.tw
Fax: [phone] Email: [e-mail]

3

AT1380A

Switching Regulator Controller for LCD Bias

Electrical Characteristics

(VCC=+3.0V, Ta=+250C)

Va lu esParameter Symbol Condition

Min. Typ. Max.

Lockout
(U.V.L.O.)

Reset voltage for
falling Vcc. OUT
remains off if Vcc is
below this level.

Startup voltage for
rising Vcc.

V

R

-- 1.8 1.9 VVCC Under voltage

--

V

TH

2.4 2.5 2.6 V

Unit

Soft start

Short circuit
detection (S.C.P.)

Sawtooth waveform
oscillator (OSC)

Error amplifier

Idle period
adjustment section

Output section

Charging current I

Voltage at soft start

V

CS

V

ts

=0V -1.5 -1.0 -0.7

SCP

-- 0.7 0.8 0.9 V

μA

completion
Charging current I

Threshold voltage V
Oscillation frequency f

Frequency input

V

CPC

OSC

f

tPC

∆V

=0V -1.5 -1.0 -0.7

SCP

-- 0.7 0.8 0.9 V

RT=3kΩ, CT=270pF

400 500 600 kHz

VCC=2.5V to 13.5V -- 2 10 %

μA

Stability
Frequency variation

f

Ta =-300C to 850C--5--%

∆T

with temperature
Input threshold

V

V

T

= 450mV 480 500 520 mV

FB

Voltage
VT input stability V
VT variation with

V

VCC=2V to 13.5V -- 5 20 mV

T∆V

Ta = -300C to 850C--1--%

T∆T

Temperature
Input bias current I

Voltage gain A
Frequency bandwidth BW AV = 0 dB -- 6 -- MHz

V

voltage range

V

Output source current I
Output sink current I
Maximum duty cycle T

V
V

Output voltage

V

V

Output source current I

Output sink current I

Pull down resistance R

VIN = 0V -1.0 -0.2 1.0

B

V

+

OM

_

OM

+

V

OM

OM

DUTY

OH1

OH2

OL1

OL2

O

O

FB

_

RT=3.3kΩ, CT=270pF
f

OSC

RB= 390Ω, IO= -15 mA
RB= 750Ω, VCC = 3.0V

= -10 mA

I

O

RB= 390Ω, IO= -15 mA

RB= 750Ω, VCC = 3.0V

= -10 mA

I

O

+

RB= 390Ω, VO = 0.9V

-

RB= 390Ω, VO = 0.3V

O

-- 70 100 145 V/V

--

0.78 0.87 -- VMaximum output

= 450mV

= 500KHz

-- 20 30 40

μA

-- 0.05 0.2 V

-- -40 -24

24 40 --

μA
μA

75 -- 85 %

1.0 1.2 -- V

0.8 1.0 -- V

-- 0.1 0.2 V

-- 0.1 0.2 V

-- -40 -30 mA

40 70 -- mA

ｋΩ

2F, No.10, Prosperity RD. II, Science-Based Industrial Park, Hsinchu 300,Taiwan, R.O.C.
Tel: [phone] WWW: http://www.aimtron.com.tw
Fax: [phone] Email: [e-mail]

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