SY21566WDQ (SQ40103WDQ)

Power Management Unit for DDR5 With 4 Buck Regulator and 2 LDOs

SY21566WDQ Power Management Unit for DDR5 With 4 Buck Regulator and 2 LDOs Datasheet

Parameters
Features
Description

Part number	SY21566WDQ
Vin (min) (V)	4.25
Vin (max) (V)	15
Channel(#)	4 Chs Buck+2 Chs LDO
Application	DDR5 Power Supply
Features	Compliant with JESD301-1 specification, ±0.75% feedback reference accuracy for Buck channels, independently programmable parameters for each channel, embedded 8-bit ADC, UVLO, OVP, OCP, OTP functions
Package	QFN5×5-35

• 4.25V to 15V wide input voltage range

• Programmable dual phase and single phase regulator for SWA and SWB

• Automatic switchover from VIN_Mgmt input supply to VIN_Bulk input supply

• Error injection capability

• Persistent error log registers

• Write protect function

• Independently programmable output voltages, power up and power down sequence for switch regulators

• Input and output power good status reporting mechanism

• Thermal shutdown protection

• Output switch regulators protection feature: output over voltage, output under voltage, output current limiter

• Output current and power measurement, output current threshold mechanism

• Temperature measurement, temperature warning threshold, critical temperature shutdown threshold

• Multi time programmable non-volatile memory

• Programmable and DIMM specific registers for customization

• General status interrupt function

• VIN_Bulk input supply protection feature: input over voltage

• Flexible open drain IO (I2C) and push pull (I3C) IO support

• 8 bits ADC

• Channel 1 and Channel 2 dual phase synchronous buck converter

--Feedback reference accuracy: ±0.75%

--Typical output voltage: 1.1V

--Programmed output voltage range: 0.6V to 1.435V

--Maximum continuous output current: 10A

--Programmable quasi-fixed switching frequency

--Output over voltage protection

--Output under voltage protection

--Cycle-by-cycle valley current limit

• Channel 3 synchronous buck converter

--Feedback reference accuracy: ±0.75%

--Typical output voltage: 1.1V

--Programmed output voltage range: 0.6V to 1.435V

--Maximum continuous output current: 5A

--Programmable quasi-fixed switching frequency

--Output over voltage protection

--Output under voltage protection

--Cycle-by-cycle valley current limit

• Channel 4 synchronous buck converter

--Feedback reference accuracy: ±0.75%

--Typical output voltage: 1.8V

--Programmed output voltage range: 1.5V to 2.835V

--Maximum continuous output current: 5A

--Programmable quasi-fixed switching frequency

--Output over voltage protection

--Output under voltage protection

--Cycle-by-cycle valley current limit

• Channel 5 LDO

--Output voltage: 0.9V to 1.2V

--Minimum output current: 20mA

• Channel 6 LDO

--Output voltage: 1.7V to 1.9V

--Minimum output current: 25mA

• Package: QFN5×5-35

• MSL rating: MSL3

The SY21566 is a high efficiency PMIC designed for Server DDR5 DIMM modules. The SY21566 meets PMIC5000 of JESD301-1 specification.

This IC integrates 4-channel synchronous Buck converter and 2-channel LDO. The device works in a wide input voltage range from 4.25V to 15V.

Channel 1 and channel 2 are dual phase Buck regulator with typical 1.1V output voltage and totally 10A average, 12A peak current capability. Interleaved control logic is integrated internally to reduce output voltage ripple. Channel 3 is also typical 1.1V output Buck regulator. The current capability is 5A average and 6A peak. Channel 4 is typical 1.8V output, 5A average and 6A peak current capability Buck regulator. Channel 5 and Channel 6 are both LDO. Channel 5 output voltage is 1.0V and channel 6 output voltage is 1.8V.

The SY21566 supplies under voltage lockout, over voltage, over current and over temperature protection to ensure reliable operation of the system.

An 8 bits ADC is integrated internally to achieve real time current and temperature measurement. The host can read the measure result through I2C/I3C interface.

The SY21566 is available in QFN5×5-35 package.

Evaluation Board

Photo of evaluation board
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EVB_SY21566WDQ

EVB File

The EVB_SY21566WDQ is intended for evaluating power management unit for DDR5 with 4 Buck regulator and 2 LDOs.

Technical Documentation

Title	Date
Silergy_Catalog_Q2_2026	2026-06-12