SC900A Datasheet, PDF (1/23 Pages) Semtech Corporation – Programmable Penta ULDO with RESET and I2C Interface

POWER MANAGEMENT
Description
SC900A
Programmable Penta ULDO
with RESET and I²C Interface
Features
The SC900A is a highly integrated power management de-
vice for low power portable applications. The device con-
tains five adjustable low-dropout linear regulators (LDOs)
with CMOS pass-devices as well as a band-gap reference,
I²C interface, and DACs to control the output voltages.
Many features of the SC900A are programmable through
the I²C interface. These include the ability to independent-
ly turn on any combination of the five regulators. All five
of the LDO output voltages are programmable in 50mV
steps from 1.45V to 3.00V for LDOs A and B, and from
1.75V to 3.30V for LDOs C, D and E. Each LDO can have
an active shutdown or nonactive shutdown program op-
tion through the interface. There is also a reset monitor
flag that is associated with LDOA. In addition, the device
has a separate programmable power good monitor flag
that activates when one or more LDOs go out of regula-
tion.
The SC900A offers significant quiescent current and
space savings to the system designer by sharing refer-
ence and biasing among five LDOs. The small and ther-
mally efficient 20-lead MLPQ package make it ideal for
use in portable products where minimizing layout area is
critical.
‹ Five LDO regulators in one package
‹ I²C interface with multiple device capability
‹ Independent I²C enable/disable of LDOs
‹ Independent I²C control of output voltages
‹ Low thermal impedance of 40°C per watt
‹ 150mV dropout at 150mA
‹ Input range from 2.7V to 5.5V
‹ Programmable power good flag
‹ Minimal number of external components
‹ Over temperature protection
‹ Small 4mm x 4mm 20-lead MLPQ package
‹ Small input/output filter capacitors
‹ Programmable VOUT range -
1.45V to 3.00V for LDOs A and B
1.75V to 3.30V for LDOs C, D and E
Applications
‹ Palmtop/Laptop computers
‹ Personal Digital Assistants
‹ Cellular telephones
‹ Battery-powered equipment
‹ High efficiency linear power supplies
Typical Application Circuit
+
- ^VBAT
4.7uF
SC900A
VIN
INA
INB
INCD
INE
EN
LDOPGD
ARST
SDA
SCL
A0
GND
LDOE
LDOD
LDOA
LDOB
LDOC
VREF
VASEL
DGND
2.2uF 2.2uF 2.2uF
0.1uF
Keypad
Baseband
Processor
Audio
Processing
Digital
Interface
2.2uF
2.2uF
LNA
Receiver
Section
TCXO
&
Synthesiser
Transmitter
PA
Section
Camera
Processing
CCD
November 14, 2005
1
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