LTC1876_15 Datasheet, PDF (10/36 Pages) Linear Technology – High Efficiency, 2-Phase, Dual Synchronous Step-Down Switching Controller and Step-Up Regulator

LTC1876
W
FUNCTIONAL DIAGRA
FREQSET
PGOOD
V_SEC
0.18µA
R6
FCB
R5
3.3V_OUT
1.19V
1M
OSCILLATOR
WINDOW
COMPARATOR
4.5V –
+
DUPLICATE FOR SECOND
CONTROLLER CHANNEL
BOOST
CLK1
CLK2
V_OSENSE1
V_OSENSE2
BINH
DROP
OUT
DET
SQ
RQ
BOT FCB
TOP ON
TG
TOP
SW
RUN/SS1
SWITCH
LOGIC
INTV_CC
BG
BOT
0.55V
+B
–
SHDN
PGND
+
FCB
–
0.8V
V_REF
I1
I2
–
– ++ –
+
0.86V
3mV
4(V_FB)
INTV_CC
30k ^SENSE+
30k ^SENSE–
V_IN
V_IN
EXTV_CC
INTV_CC
+^5V
SGND
4.8V +
–
STBYMD
5V
LDO
REG
INTERNAL
SUPPLY
SLOPE
COMP
1.2µA
6V
45k
SHDN
RST
4(V_FB)
45k
2.4V
EA
OV
V_FB
0.80V
0.86V
RUN
SOFT
START
V_OSENSE
I_TH
RUN/SS
INTV_CC
V_IN
D_B
C_B
+
D₁
R_SENSE
D_SEC
R2
R1
C_C
C_C2
R_C
C_IN
C_OUT
C_SEC
C_SS
BOOST
REGULATOR
AUXSD
AUXV_IN
L3
1.26V
V_REF
AUXV_FB
EA_AUX
+
–
R7
R8
A1_AUX
–
C_{C +}
R_C
Σ
RAMP
GENERATOR
RQ
SQ
1.2MHz
OSCILLATOR
OSC_AUX
D5
AUXSW
AUXPGND
AUXV_OUT
+
C_OUTAUX
1876 FD/F02
V_OUT
Figure 2
1876fa
10