BD3538F_10 Datasheet, PDF (1/11 Pages) Rohm – Termination Regulators for DDR-SDRAMs

High Performance Regulators for PCs
Termination Regulators
for DDR-SDRAMs
BD3538F,BD3538HFN
No.10030EAT33
Description
BD3538F/HFN is a termination regulator compatible with JEDEC DDR-SDRAM, which functions as a linear power supply
incorporating an N-channel MOSFET and provides a sink/source current capability up to 1A respectively. A built-in
high-speed OP-AMP specially designed offers an excellent transient response. Requires 3.3 volts or 5.0 volts as a bias
power supply to drive the N-channel MOSFET. Has an independent reference voltage input pin (VDDQ) and an
independent feedback pin (VTTS) to maintain the accuracy in voltage required by JEDEC, and offers an excellent output
voltage accuracy and load regulation. Also has a reference power supply output pin (VREF) for DDR-SDRAM or a memory
controller. When EN pin turns to “Low”, VTT output becomes “Hi-Z” while VREF output is kept unchanged, compatible with
“Self Refresh” state of DDR-SDRAM.
Features
1) Incorporates a push-pull power supply for termination (VTT)
2) Incorporates a reference voltage circuit (VREF)
3) Incorporates an enabler
4) Incorporates an undervoltage lockout (UVLO)
5) Employs SOP8 package
6) Employs HSON8 package
7) Incorporates a thermal shutdown protector (TSD)
8) Operates with input voltage from 2.7 to 5.5 volts
9) Compatible with Dual Channel (DDR-II)
Use
Power supply for DDR I / II / III - SDRAM
●Absolute Maximum Ratings
Parameter
Input Voltage
Enable Input Voltage
Termination Input Voltage
VDDQ Reference Voltage
Symbol
VCC
VEN
VTT_IN
VDDQ
Ratings
BD3538F
7 ^*1*2
7 ^*1*2
7 ^*1*2
7 ^*1*2
BD3538HFN
7 ^*1*2
7 ^*1*2
7 ^*1*2
7 ^*1*2
Unit
V
V
V
V
Output Current
Power Dissipation1
Power Dissipation2
Power Dissipation3
ITT
1
Pd1
560 ^*3
Pd2
690 ^*4
Pd3
-
1
A
630 ^*5
mW
1350 ^*6
mW
1750 ^*7
mW
Operating Temperature Range
Tstg
-40～+105
-40～+105
℃
Storage Temperature Range
Tjmax
-55～+150
-55～+150
℃
Maximum Junction Temperature
Tjmax
+150
+150
℃
*1 Should not exceed Pd.
*2 Instantaneous surge voltage, back electromotive force and voltage under less than 10% duty cycle.
*3 Reduced by 4.48mW for each increase in Ta of 1℃ over 25℃(With no heat sink).
*4 Reduced by 5.52mW for each increase in Ta of 1℃ over 25℃(When mounted on a board 70mm×70mm×1.6mm Glass-epoxyPCB).
*5 Reduced by 5.04mW/℃ for each increase in Ta≧25℃ (when mounted on a 70mm×70mm×1.6mm glass-epoxy board, 1-layer)
On less than 0.2% (percentage occupied by copper foil.
*6 Reduced by 10.8mW/℃ for each increase in Ta≧25℃ (when mounted on a 70mm×70mm×1.6mm glass-epoxy board, 1-layer)
On less than 7.0% (percentage occupied by copper foil.
*7 Reduced by 14.0mW/℃ for each increase in Ta≧25℃ (when mounted on a 70mm×70mm×1.6mm glass-epoxy board, 1-layer)
On less than 65.0% (percentage occupied by copper foil.
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2010.05 - Rev.A