GENERAL DESCRIPTION

The ADP5042 combines one high performance buck regulator and two low dropout (LDO) regulators 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.

FEATURES

Input voltage range: 2.3 V to 5.5 V

One 0.8 A buck regulator

Two 300 mA LDOs

20-lead, 4 mm × 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

Uses tiny multilayer inductors and capacitors

Mode pin selects forced PWM or auto PFM/PSM modes

100 duty cycle low dropout mode

LDOs key specifications

Low VIN from 1.7 V to 5.5 V

Stable with1 μF ceramic output capacitors

High PSRR, 60 dB PSRR up to 1 kHz/10 kHz

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