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