Multi-output Regulators with Supervisory and Watchdog Timers Reduce Component Count, Increase Power Density and Reliability

Unlike discrete power solutions that require up to 14 components and 126 mm2 of board space, these highly integrated regulators provide a more integrated circuit solution using only nine components and 50 mm2 of board space to increase performance and reliability and lower system cost.

More About the ADP5041 and ADP5040 Multi-output Regulators
The ADP5041 and ADP5040 are ideal power management companions to mid-range FPGA, microprocessor and DSP systems where core, IO and memory voltages are necessary. The ADP5041 regulator’s on-chip watchdog timer provides greater reliability by monitoring code execution integrity in processor-based systems and resetting the processor if it fails to strobe within a preset timeout period. The ADP5041 also features a high accuracy (±1.5% over temperature) reset generator that can be externally programmed to monitor low-voltage power-supply rails. A wide range of ordering options also is available to address multiple reset and watchdog timings.

The ADP5041 has a special circuit that detects a three-state condition when applied to the watchdog refresh input at the WDI pin typically controlled by a processor/DSP output port. When the processor sets this port in three-state mode, the watchdog refresh timer is disabled, preventing a watchdog reset to the processor. This feature is important when supporting processor/DSP sleep operation where the core is disabled and watchdog timer cannot be refreshed.

The ADP5041 and ADP5040 multi-output regulators reduce thermal dissipation by using high-efficiency switching regulators with up 96 percent buck power efficiency. For low-noise analog circuit applications, the LDOs maintain a power supply rejection greater than 60 dB for frequencies as high as 10 kHz while operating with a low headroom voltage. The ADP5041 and ADP5040 also provide a three-rail system power supply (1.2-A buck regulator and two 300-mA LDOs) with adjustable output voltages, which allows output voltages to be easily set using an external resistor divider network. The 3-MHz buck regulator switching frequency allows small ceramic inductors to be used to further reduce solution size and cost. These features allow the ADP5041 and ADP5040 to be easily and quickly modified for a variety of applications with short product design schedules such as portable medical and industrial devices.

ADP5041 andADP5040 Multi-output Regulator Key Features:
• One 1.2-A buck regulator
Output voltage range = 0.8 V to 3.8 V
Current mode topology for excellent transient response
3-MHz operating frequency
Peak efficiency up to 96 percent
Regulator total accuracy: ±3 percent
• Two 300-mA LDOs
Output voltage range = 0.8 V to 4.75 V
Low input supply voltage from 1.7 V to 5.5 V
Stable with 2.2-μF ceramic output capacitors
High PSRR = 60-dB up to 10 kHz
Low output noise = 60 μV rms typical output noise at 1.2 V
Low dropout voltage = 150 mV at 300-mA load