The ADP1878 / ADP1879 are versatile current mode, synchronous step-down controllers. They provide superior transient response, optimal stability, and current-limit protection by using a constant on-time, pseudo fixed frequency with a programmable current limit, current control scheme. In addition, these devices offer optimum performance at low duty cycles by using a valley, current mode control architecture. This allows the ADP1878 / ADP1879 to drive all N-channel power stages to regulate output voltages to as low as 0.6 V.
The ADP1879 is the power saving mode (PSM) version of the
device and is capable of pulse skipping to maintain output
regulation while achieving improved system efficiency at light
loads (see the ADP1879 Power Saving Mode (PSM) section for
more information).
Available in three frequency options (300 kHz, 600 kHz, and
1.0 MHz, plus the PSM option), the ADP1878 / ADP1879 are well
suited for a wide range of applications that require a single-input
power supply range from 2.95 V to 20 V. Low voltage biasing is
supplied via a 5 V internal low dropout regulator (LDO).
In addition, soft start, programmability is included to limit
input in-rush current from the input supply during startup and
to provide reverse current protection during precharged output
conditions. The low-side current sense, current gain scheme and
integration of a boost diode, along with the PSM/forced pulsewidth
modulation (PWM) option, reduce the external part count
and improve efficiency.
The ADP1878/ADP1879 operate over the −40°C to +125°C
junction temperature range and are available in a 14-Lead
LFCSP_WD package.
APPLICATIONS
- Telecom and networking systems
- Mid to high-end servers
- Set-top boxes
- DSP core power supplies
