LTC3729_15 Datasheet, PDF (9/30 Pages) Linear Technology – 550kHz, PolyPhase, High Efficiency, Synchronous Step-Down Switching Regulator

LTC3729
PIN FUNCTIONS G Package/UH Package
EXTV_CC (Pin 22/Pin 21): External Power Input to an
Internal Switch . This switch closes and supplies INTV_CC,
bypassing the internal low dropout regulator whenever
EXTV_CC is higher than 4.7V. See EXTV_CC Connection in
the Applications Information section. Do not exceed 7V
on this pin and ensure V_EXTVCC ≤ V_INTVCC.
V_IN (Pin 24/Pin 23): Main Supply Pin. Should be closely
decoupled to the IC’s signal ground pin.
CLKOUT (Pin 28/Pin 27): Output Clock Signal available
to daisychain other controller ICs for additional MOSFET
driver stages/phases.
FUNCTIONAL DIAGRAM
PLLIN
F_IN
PHASE DET
50k
PLLLPF
R_LP
CLKOUT
CLK1
C_LP
OSCILLATOR _CLK2
PHASMD
PHASE LOGIC
±2µA
DIFFOUT
40k
V_OS–
V_OS+
40k
40k
A1
–
+
40k
DUPLICATE FOR SECOND
CONTROLLER CHANNEL
INTV_CC
V_IN
BOOST
D_B
DROP
OUT
TG
C_B
TOP
DET
BOT FCB
FORCE BOT
SW
SQ
RQ
SWITCH
LOGIC
INTV_CC
BG
BOT
PGND
I1
–+
SHDN
INTV_CC
L
30k ^SENSE+
+
C_IN
PGOOD
V_IN
V_IN
EXTV_CC
INTV_CC
+^5V
SGND
0.86V
0.80V
EAIN
0.74V
V_REF
4.7V +
5V
–
LDO
REG
INTERNAL
SUPPLY
0.86V
4(V_FB)
SLOPE
COMP
1.2µA
6V
45k
SHDN
RST
4(V_FB)
45k
2.4V
EA
OV
RUN
SOFT
START
30k ^SENSE–
R_SENSE
C_OUT
0.80V
EAIN
V_OUT
R1
R2
0.86V
I_TH ^CC
R_C
RUN/SS
C_SS
3729 FBD
3729fb
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