BD3531F_15 Datasheet, PDF (1/19 Pages) Rohm – Termination Regulator for DDR-SDRAMs

Datasheet
Termination Regulator for DDR-SDRAMs
BD3531F
General Description
BD3531F is a termination regulator that complies with
JEDEC requirements for DDR-SDRAM. This linear
power supply uses a built-in N-channel MOSFET and
high-speed OP-AMPS specially designed to provide
excellent transient response. It has a sink/source
current capability up to 1.5A and has a power supply
bias requirement of 5.0V for driving the N-channel
MOSFET. By employing an independent reference
voltage input (VDDQ) and a feedback pin (VTTS), this
termination regulator provides excellent output voltage
accuracy and load regulation as required by JEDEC
standards. Additionally, BD3531F has a reference
power supply output (VREF) for DDR-SDRAM or for
memory controllers. Unlike the VTT output that goes to
“Hi-Z” state, the VREF output is kept unchanged when
EN input is changed to “Low”, making this IC suitable
for DDR-SDRAM under “Self Refresh” state.
Features
 Incorporates a Push-Pull Power Supply for
Termination (VTT)
 Incorporates a Reference Voltage Circuit (VREF)
 Incorporates an Enabler
 Incorporates an Undervoltage Lockout (UVLO)
 Incorporates a Thermal Shutdown Protector (TSD)
 Compatible with Dual Channel (DDR-II)
Applications
Power supply for DDR I/II - SDRAM
Key Specifications
 Termination Input Voltage Range: 1.0V to 5.5V
 VCC Input Voltage Range:
4.5V to 5.5V
 Output Voltage:
1/2xVVDDQ V(Typ)
 Output Current:
1.5A(Max)
 High Side FET ON-Resistance:
0.4Ω(Typ)
 Low side FET ON-Resistance:
0.4Ω(Typ)
 Standby Current:
0.8mA (Typ)
 Operating Temperature Range: -10°C to +100°C
Package
W(Typ) x D(Typ) x H(Max)
SOP8
5.00mm x 6.20mm x 1.71mm
Typical Application Circuit, Block Diagram
VCC
VDDQ
VTT_IN
VCC
Reference
Block
VDDQ
VCC
50kΩ
UVLO
VCC
50kΩ
UVLO
Enable
EN
Thermal
Protection
TSD
GND
VCC
VTT_IN
TSD
VCC EN
UVLO
TSD
EN
UVLO
VTT
VTTS
VREF
VTT
½x
VDDQ
○Product structure：Silicon monolithic integrated circuit
www.rohm.com
© 2015 ROHM Co., Ltd. All rights reserved.
TSZ22111・14・001
○This product has no designed protection against radioactive rays
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TSZ02201-0J2J0A900950-1-2
02.Nov.2015 Rev.001