sc1116 Semtech Corporation, sc1116 Datasheet - Page 4

• Manufacturer Part Number: sc1116
• Description: Sc1116 Linear Fet Controller For Ddr Supplies
• Manufacturer: Semtech Corporation

Overview
The SC1116 linear controller is designed to meet the
JEDEC specifications for termination of DDR-SDRAM.
Double Data Rate (DDR) memory is clocked at the same
speed as older SDRAM (synchronous dynamic random
access memory), yet handles twice the amount of data
by using the rising and falling edge of the clock signal for
data transfers. Another difference is that DDR memory
requires 2.5V instead of 3.3V used by standard SDRAM.
The other feature that separates DDR memory from a
conventional type is employment of the V
voltage. Main requirements for the V
track variations of V
current, and absorb (sink) current.
POWER MANAGEMENT
Application Information
2007 Semtech Corp.
V DDQ=2.5V
V ref=1.25V
V cc=5V
1 00 uF
C 1
3 2m
DDQ
and be able to supply (source)
0 .1uF
1 uF
C 3
C 2
1
2
3
VCC
G ND
R EF
SC1116
TT
U 1
are that it must
DRVH
DRVL
TT
FB
– termination
6
5
4
4.7nF
C 4
R3
1 k
IR37 14
Q 1
Figure 1.
4
R4
1 k
The SC1116 controller offers a low cost solution for DDR
termination voltage regulation by using external pass el-
ements (MOSFETs). Having the flexibility of choosing the
MOSFETs allows for optimization on the basis of cost/
size/performance of the specific application.
Test Circuit & Waveforms
The test circuit is shown below in Figure 1.
Note that V
inaccuracy caused by resistor divider.
4 .7nF
C 5
IR37 14
Q 2
2 70 uF
2 2m
C 6
V TT =1.25V typ
REF
Cu rrent
Pro be
voltage is supplied externally to eliminate
Pu lse loa d, dc=50%
0A to 6A Step
Iso urce/ Isink
+/-3A
2xIsin k
3A Isource
Isin k
www.semtech.com
SC1116
E lectronic
Po wer
Su pp ly
Loa d