ADP5043 Micro-PMU with 0.8 A Buck, 300 mA LDO, Supervisory, Watchdog, and Manual Reset

The ADP5043 combines one high performance buck regulator and one low dropout regulators (LDO) in a small 20-lead LFCSP to meet demanding performance and board space requirements.

The high switching frequency of the buck regulator enables use of tiny multilayer external components and minimizes the board space.

The MODE pin selects the buck mode of operation. When set to logic high, the buck regulators operate in forced PWM mode. When the MODE pin is set to logic low, the buck regulators operate in PWM mode when the load is around the nominal value. When the load current falls below a predefined threshold the regulator operates in power save mode (PSM) improving the light-load efficiency.

The low quiescent current, low dropout voltage, and wide input voltage range of the ADP5043 LDOs extend the battery life of portable devices. The LDO maintain power supply rejection greater than 60 dB for frequencies as high as 10 kHz while operating with a low headroom voltage.

Each regulator is activated by a high level on the respective enable pin. The ADP5043 is available with factory programmable default output voltages and can be set to a wide range of options.

The ADP5043 contains supervisory circuits that monitor power supply voltage levels and code execution integrity in microprocessor-based systems. They also provide power-on reset signals. An on-chip dual watchdog timer can reset the microprocessor or power cycle the system (Watchdog 2) if it fails to strobe within a preset timeout period.

Features and Benefits

Input voltage range: 2.3V to 5.5V
One 0.8 A buck regulator
One 300 mA LDO
20-lead, 4 mm x 4 mm LFCSP package
Initial regulator accuracy: ±1%
Overcurrent and thermal protection
Soft start
Undervoltage lockout
Open drain processor reset with threshold monitoring
±1.5% threshold accuracy over the full temperate range
Guaranteed reset output valid to VCC = 1 V
Dual watchdog for secure systems
Watchdog 1 controls reset
Watchdog 2 controls reset and regulators power cycle

Buck key specifications
Current mode topology for excellent transient response
3 MHz operating frequency
Mode pin selects forced PWM or auto PFM/PSM modes
LDO key specifications
Low VIN from 1.7 V to 5.5 V
Low output noise: 110 μV rms typical output noise at VOUT = 2.8 V
Low dropout voltage: 150 mV at 300 mA load
-40°C to +125°C junction temperature range
Additional Buck specifications
Uses tiny multilayer inductors and capacitors
100% duty cycle low dropout mode
Additional LDO Specifications
High PSRR, 60 dB PSRR up to 1 kHz/10 kHz
Stable with1 μF ceramic output capacitors