Analog Devices ADP1875

Description

The ADP1874/ADP1875 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 ADP1874/ADP1875 to drive all N-channel power stages to regulate output voltages to as low as 0.6 V.

The ADP1875 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 ADP1875 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 ADP1874/ADP1875 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 pulse-width modulation (PWM) option, reduce the external part count and improve efficiency.

The ADP1874/ADP1875 operate over the −40°C to +125°C junction temperature range and are available in a 16-lead QSOP package.

Features

• Power input voltage range: 2.95 V to 20 V
• On-board bias regulator
• Minimum output voltage: 0.6 V
• 0.6 V reference voltage with ±1.0% accuracy
• Supports all N-channel MOSFET power stages
• Available in 300 kHz, 600 kHz, and 1.0 MHz options
• No current-sense resistor required
• Power saving mode (PSM) for light loads (ADP1875 only)
• Resistor programmable current limit
• Power good with internal pull-up resistor
• Externally programmable soft start
• Thermal overload protection
• Short-circuit protection
• Standalone precision enable input
• Integrated bootstrap diode for high-side drive
• Starts into a precharged output
• Available in a 16-lead QSOP package

Remarks:1.Table 8,11. Recommended InductorRefer page no.27 And 35

2.Table 10. External Component ValuesRefer page no.34

Typical applications

• DSP core power supplies
• Telecom and networking systems
• Set-top boxes
• Mid- to high-end servers

More information

• Datasheet
• IC product information