G5616 Datasheet, PDF (1/4 Pages) Global Mixed-mode Technology Inc – Complete DDR, DDRII and DDRIII Memory Solution Synchronous Buck PWM Controller, 3A LDO, Buffered Reference

Global Mixed-mode Technology
G5616
Complete DDR, DDRII and DDRIII Memory Solution
Synchronous Buck PWM Controller, 3A LDO,
Buffered Reference
Features
•Synchronous Buck Controller (VDDQ)
„ Ultra-High Efficiency
„ No Current-Sense Resistor (Lossless ILIMIT)
„ Quasi-PWM with 100ns Load-Step Response
„ 1.8V(DDRII) /1.5V(DDRIII) Fixed or Adjustable
to 2.5V(DDR) or 0.75V to 3.6V Adjustable Out-
put Range
„ 2V to 24V Battery Input Range
„ 400kHz Switching Frequency
„ OVP & UVP of VDDQ Output
„ Drives Large Synchronous-Rectifier FETs
„ Power-Good Indicator
•3-A LDO (VTT), Buffered Reference (VTTREF)
„ Support DDR (1.25 VTT) , DDR II (0.9 VTT) and
DDRIII(0.75 VTT) Requirements
„ VLDOIN Voltage Range: 1.2V to 3.6V
„ Requires Only 20µF Ceramic VTT Output Ca-
pacitance
„ Supports High-Z in S3 and Soft-Off in S5
„ Integrated Divider Tracks 1/2 VDDQSNS for
Both VTT and VTTREF
„ Remote Sensing (VTTSNS)
„ ±20mV Accuracy for VTT and VTTREF
„ 10mA Buffered Reference (VTTREF)
„ Built-In Soft-Start to Reduce the VLDOIN Surg-
ing Current
„ Over Current Protection of VTT Output
„ Thermal Shutdown Protection
Applications
„ Notebook Computers
„ CPU Core Supply
„ Chipset/RAM Supply as Low as 0.75V
„ 1.8V and 2.5V I/O Supply
General Description
The G5616 is intended for DDR/SSTL-2, D-
DRII/SSTL-18 and DDRIII memory systems. It inte-
grates a synchronous buck PWM controller with a 3-A
sink-source linear regulator and buffered reference.
The PWM controller uses constant on-time control
scheme to handle wide input/output voltage ratios with
ease and provides 100ns “instant-on” response to
load transients while maintaining a relatively constant
switching frequency. The G5616 achieves high effi-
ciency at a reduced cost by eliminating the cur-
rent-sense resistor found in traditional current-mode
PWMs. Efficiency is further enhanced by an ability to
drive very large synchronous rectifier MOSFETs. Sin-
gle-stage buck conversion allows these devices to
directly step down high-voltage batteries for the high-
est possible efficiency.
The 3A sink/source tracking termination regulator is
specifically designed for low-cost/ low-external com-
ponent count systems. The regulator contains a high
speed operational amplifier that provides fast load
transient response with only 20µF (2x10µF) of ceramic
output capacitance. The G5616 supports remote
sensing functions and all features required to power
the DDR /DDRII /DDRIII VTT bus termination accord-
ing to the JEDEC specification. In addition, the G5616
includes integrated sleep-state controls placing VTT in
High-Z in S3 (suspend to RAM) and soft-off for VTT
and VTTREF in S5 (Shutdown).
The G5616 provides OVP, UVP, over current and
thermal shutdown protection functions and is available
in a 20-pin 3X3 TQFN package and 24-pin 4X4 TQFN
includes over voltage protection.
Ordering Information
ORDER
NUMBER
G5616RZ1U
G5616R51U
Note: RZ: TQFN3X3-20
1: Bonding Code
U : Tape & Reel
MARKING
5616
5616
R5: TQFN4X4-24
TEMP.
RANGE
-40°C to +85°C
-40°C to +85°C
PACKAGE
(Green)
TQFN3X3-20
TQFN4X4-24
Ver: 1.5
Oct 26, 2012
TEL: [phone]
http://www.gmt.com.tw
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