SC905A Datasheet, PDF (1/23 Pages) Semtech Corporation – CDMA Cellular Phone Power Management IC

POWER MANAGEMENT
Description
The SC905A is a power management integrated circuit
(PMIC) designed for the latest CDMA chip sets. The device
provides four general purpose low dropout regulators
(LDOs), and five low noise LDOs designed for analog
circuits. The VMOT LDO can be used as a general purpose
regulator or as an adjustable motor drive output that can
supply up to 150mA to drive a vibrator motor.
Each LDO’s enable and output voltage are controlled via
the I²C bus. The VTCXO output has an external enable pin
that can be used instead of the register bit when timing is
critical for minimizing sleep current. The VMOT also has
an external enable pin for additional flexibility.
Initial power-on is achieved by activating either the ON
button, the battery charger, or the HFPWR signal, and the
PGOOD input is used by the microprocessor to latch power
on or disable the device.
SC905A
CDMA Cellular Phone
Power Management IC
Features
9 LDO Linear Regulators
CORE: 1.35V - 2.90V @ 300mA
ANA: 2.55V - 2.90V @ 200mA
PAD: 1.75V - 3.30V @ 300mA
RX: 2.75V - 3.10V @ 150mA
TX: 2.75V - 3.10V @ 150mA
TCXO: 2.75V - 3.10V @ 80mA
PLL: 2.75V - 3.10V @ 80mA
Camera: 1.75V - 3.30V @ 100mA
Motor Drive: 1.75V - 3.30V @ 150mA
I²C Interface for Microprocessor Control
Less than 1μA Quiescent Current in Shutdown
65dB PSRR for Analog LDOs
Over-Temperature Protection
Power-On Control
Small 5mm x 5mm 32-Pin MLPQ Package
The thermally-efficient MLPQ-32 package combined with
miniature ceramic bypass capacitors minimize required
PCB area, making the SC905A ideal for space-conscious
portable applications.
Applications
CDMA Cellular Handsets
PDAs/Smartphones
Wireless VOIP Handsets
Typical Application Circuit
Battery
Charger
Circuit
Handsfree
Option
MOTOR
ON/OFF
SC905A
VBAT
CHPWR
IN 1
EN_TCXO
IN 2
IN 3
E N_MO T
IN 4
IN 5
ON
HFPWR
PGOOD
SDA
SCL
P W RO N
RESB
IN 6
DVIN
V CO RE
VPAD
VANA
VTCXO
VPLL
VTX
0. 1μF
VMOT
BP
A G ND
VRX
VCAM
VPSEL
VCSEL
DG ND
VBAT
10μF
B A TTE RY
1μF
1μF
1μF
1μF
1μ F
1μF
Baseband
1μ F
Processor
1μF
Keypad
Audio
Processing
TCXO
+
Synthesiser
PLL
Transmitter ^PA
Section
Receiver ^LNA
Section
Camera
Module
Digital
Interface
June 7, 2006
1
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