ltc3717-1 Linear Technology Corporation, ltc3717-1 Datasheet - Page 7

• Manufacturer Part Number: ltc3717-1
• Description: Wide Operating Range, No Rsense Step-down Controller For Ddr/qdr Memory Termination
• Manufacturer: Linear Technology Corporation

PI FU CTIO S
BOOST (Pin 28): Boosted Floating Driver Supply. The (+)
terminal of the bootstrap capacitor C
pin swings from a diode voltage drop below INTV
V
FU CTIO AL DIAGRA
IN
U
+ INTV
U
U
CC
.
0.7V
U
V
RNG
3
240k
1.4V
0.7V
V
1
t
V
I
ON
THB
REF
ON
1
U
=
10
I
V
CMP
I
VON
ION
2.4V
+
–
Q1
80k
R2
(10pF)
6 I
+
ON
R1
40k
20k
Q2
EA
5.7 A
R
ON
–
W
B
R
S
–
+
4
connects here. This
Q
I
REV
0.6V
I
TH
Q5
R
C
–
C
C1
SS
+
CC
4.7V
+
up to
0.6V
–
SHDN
RUN
SHDN
ON
OV
15 EXTV
RUN/SS (Pin 31): Run Control and Soft-Start Input. A
capacitor to ground at this pin sets the ramp time to full
output current (approximately 3s/ F) and the time delay
for overcurrent latchoff (see Applications Information).
Forcing this pin below 0.8V shuts down the device.
SWITCH
31
LOGIC
CC
RUN/SS C
1.2 A
UV
OV
0.8V
REF
REG
6V
5V
+
–
+
–
SS
3/10V
11/30V
SENSE
SENSE
PGOOD
BOOST
INTV
DRV
PGND
SW
TG
BG
REF
16 V
28
27
24
17
18
19
20
21
23
2
REF
CC
CC
+
–
IN
37171 FD01
C
+
VCC
C
B
R4
40k
C
IN
D
B
20k
R3
M1
M2
V
IN
+
SGND
L1
V
7
5
FB
C
OUT
LTC3717-1
V
OUT
sn37171 37171fs
7