Date: 15/03/2010

ADI's new buck controller and switching regulator power ICs for PoL applications

Analog Devices' (ADI) new ADP1870 and ADP1871 synchronous buck controllers use constant on-time and valley current-mode techniques to drive all N-channel power MOSFETs. ADI says these devices offer superior transient response due to the use of a constant on-time, current-mode control system. The applications suggested are intermediate rail or point-of-load generation in consumer, industrial and instrumentation, and telecommunications and networking applications.

Low duty cycle is no issue with these devices and are available in frequency options of 300 kHz, 600 kHz, and 1 MHz.
During power-saving mode ADP1871 does a pulse skipping to maintain output regulation while improving system efficiency at light loads. Low-voltage biasing is supplied through a 5-V internal LDO (low-dropout oscillator).

The other features and benefits:
Both regulators feature an internally-fixed soft-start period to limit input in-rush current from the input supply during startup and to provide reverse current protection during soft-start for a pre-charged output.
0.6-V reference voltage with ±1.0 percent accuracy allows devices to be used in low-voltage, high-accuracy, point-of-load applications.
Precision-enable ensures precise turn-on with internal soft-start

Operating Temp Range: -40°C to +125°C
Package: 10-Lead MSOP

Analog Devices has also introduced the ADP2300 and ADP2301 non-synchronous dc-to-dc switching regulators. The new 20V 1.2A (amp) step-down, dc-to-dc switching regulators integrate a high-side MOSFET delivering efficiencies above 90 percent. The new regulators feature internal loop compensation, integrated soft-start circuitry and bootstrap diodes. These power ICs are suitable for intermediate power bus and point-of-load regulation to power processor, FPGA and DSP, and precision analog chips in applications such as consumer electronics and industrial and communications infrastructure equipment.

These ADP2300 and ADP2301 operate from input voltage range from 3 V to 20V. The output voltage is adjustable from 0.8 V to 90 percent of input voltage (VIN). The regulator normally operate in current-mode, fixed-frequency PWM (pulse-width modulation) architecture and during light loads the regulators automatically switch to PFM (pulse frequency modulation) mode to reduce power loss. A precision enable pin allows the regulator to be turned on at a precise input voltage for sequencing of multiple devices. The protection features include OCP (overcurrent protection), UVLO (undervoltage lockout) and TSD (thermal shutdown).

Operating Temp Range: -40°C to +125°C
Package: 3mm x 3mm TSOT

Availability: Now
Price: $1.01 in 1K pieces

For details visit www.analog.com