AT73C239_14 Datasheet, PDF (1/31 Pages) ATMEL Corporation – Independent 2.5V to 3.6V Auxiliary Supply for Backup Section

Features
• Main Supply 3.0V to 3.6V
• Independent 2.5V to 3.6V Auxiliary Supply for Backup Section
• Internal State Machine for Startup
• 25 mA/1.8V-2.75V Linear Low Drop Out Regulator with High PSRR and Low Noise
(LDO1)
• 30 mA/1.5V-1.8V Linear Low Drop Out Regulator with High PSRR and Low Noise
(LDO2)
• 60 mA/1.23V-1.5V-1.8V Linear Low Drop Out Regulator with High PSRR (LDO3)
• 2 mA/1.2V-1.5V-1.8V Linear Low Drop Out Regulator with Very Low Quiescent Current
(LDO4)
• HPBG Economic High Performance Voltage Reference for LDO Supply to RF Sections
• LPBG Low Power Voltage Reference to LDO4 During Backup Battery Operation
• Internal Oscillator Generates Internal Master Clock
• Internal Reset Generator for Main Supply
• Additional External Reset Input
• Two Wire Interface (TWI) for Independent Activation and Output Voltage Programming
for Each LDO
• Available in 3 x 3 x 0.9 mm 16-pin QFN Package
• Applications: GPS Modules, WLAN Devices, Wireless Modules
1. Description
The AT73C239 is a four-channel Power Supply Power Management Unit (PMU) avail-
able in a QFN 3 x 3 mm package. It is a fully integrated, low cost, combined Power
Management device for wireless modules, GPS and WLAN devices. It integrates four
Linear Low Drop Out (LDO) Regulators, three of which provide high-accuracy RF per-
formance and one (LDO4) with very low quiescent current that is supplied by an
external backup battery. A Low Power Bandgap (LPBG) requiring no external capaci-
tor for decoupling, is used as reference voltage for LDO4 and starts when VBAT is
present. LDO4 regulates output voltage with extremely low quiescent current, maxi-
mizing the lifetime of the backup battery. An Internal State Machine manages the
startup of the other LDOs in the order of LDO3 then LDO1 then LDO2. An economic
High Power Bandgap (HPBG) provides highly accurate, low noise voltage reference
to LDOs 1, 2, 3. HPBG operates in switching mode thereby decreasing its current con-
sumption and becomes inactive when not directly supplied by VIN current. When the
RF LDOs are in idle mode, quiescent current is decreased to a minimum.
The AT73C239 features a Two-wire Interface (TWI) to increase the efficiency of the
system by disabling LDOs when not needed.
Power
Management
and Analog
Companions
(PMAAC)
AT73C239
4-channel
Power
Management for
Wireless
Modules
6201C–PMAAC–31-Jul-07