LTC1929 LINER [Linear Technology], LTC1929 Datasheet - Page 5

• Manufacturer Part Number: LTC1929
• Description: 2-Phase, High Efficiency, Synchronous Step-Down Switching Regulator
• Manufacturer: LINER [Linear Technology]

PI FU CTIO S
PGND (Pin 20): Driver Power Ground. Connects to sources
of bottom N-channel MOSFETS and the (–) terminals of
C
INTV
Dropout Regulator and the EXTV
control circuits are powered from this voltage source.
Decouple to power ground with a 1 F ceramic capacitor
placed directly adjacent to the IC and minimum of 4.7 F
additional tantalum or other low ESR capacitor.
FU CTIO AL DIAGRA
R
C
IN
F
LP
LP
IN
U
.
U
CC
V
IN
+
5V
(Pin 21): Output of the Internal 5V Linear Low
DIFFOUT
AMPMD
PLLLPF
EXTV
INTV
PLLIN
SGND
V
V
V
U
OS
OS
IN
CC
CC
–
+
50k
U
OSCILLATOR
4.7V
0V POSITION
PHASE DET
U
+
–
0.8V
CLK1
CLK2
INTERNAL
SUPPLY
+
–
V
LDO
REG
5V
CC
REF
A1
Switch. The driver and
W
DUPLICATE FOR
SECOND CHANNEL
V
IN
1.2 A
6V
4(V
FB
SLOPE
COMP
)
I1
S
R
–
+
Q
Q
–
DROP
OUT
DET
45k
EXTV
Switch . This switch closes and supplies INTV
ing the internal low dropout regulator whenever EXTV
higher than 4.7V. See EXTV
tions Information section. Do not exceed 7V on this pin
and ensure V
V
to the IC’s signal ground pin.
+
IN
4(V
SHDN
(Pin 24): Main Supply Pin. Should be closely decoupled
FB
)
BOT
FORCE BOT
CC
SHDN
(Pin 22): External Power Input to an Internal
START
45k
SOFT
RUN
2.4V
OV
EA
EXTVCC
SWITCH
–
+
+
–
LOGIC
V
FB
0.80V
0.86V
TOP
BOT
INTV
CC
INTV
V
30k
30k
INTVCC
CC
SENSE
SENSE
BOOST
RUN/SS
CC
PGND
EAIN
SW
TG
BG
I
TH
.
Connection in the Applica-
+
–
C
C
INTV
R
R2
SENSE
R1
CC
C
R
SS
L
C
C
D
B
LTC1929
B
V
IN
CC,
bypass-
+
CC
5
C
IN
is