LTC3838-2_15 Datasheet, PDF (51/56 Pages) Linear Technology – Dual, Fast, Accurate Step-Down DC/DC Controller with xternal Reference Voltage and Dual Differential Output Sensing

TYPICAL APPLICATIONS
LTC3838-2
V_IN
3.3V TO 14V
5V TO 5.5V EXTERNAL
+ _CIN1
180µF
C_IN2
22µF
×4
V_OUT1
1.2V
R_S1
L1
M1
0.0015Ω 0.47µH
20A
+ C_OUT1
C_OUT2
100µF
330µF
×2
×2
2.2Ω
1µF
100Ω
100Ω
1nF
0.1µF
LTC3838-2
V_IN
SENSE1^–
SENSE2^–
SENSE1⁺
SENSE2⁺
100Ω
1nF _100Ω
0.1µF
BOOST1
BOOST2
TG1
DB1
TG2
DB2
M2
L2
R_S2
0.47µH 0.0015Ω
2.2Ω
1µF
SW1
4.7µF
DRV_CC1
INTV_CC
BG1
SW2
DRV_CC2
EXTV_CC
BG2
C_OUT3 +
330µF
×2
C_OUT4
100µF
×2
PGND
EXTV_REF2
V_REF2+
0.8V TO 1.2V
10k
V_OUTSENSE1+
V_DFB2+
10k
10k
10k
V_REF2–
100k
V_{OUTSENSE1–}
PGOOD1 _PGOOD1
0.01µF
V_DFB2–
PGOOD2 ^PGOOD2
0.01µF
100k
V_OUT2
0.8V TO 1.2V
20A
47pF
470pF
23.2k
TRACK/SS1 TRACK/SS2
ITH1
ITH2
47pF
470pF
12.7k
137k ^DTR1
RT
SGND
RUN1
DTR2
PHASMD
MODE/PLLIN
CLKOUT
RUN2
38382 F19
C_IN1: SANYO 16SVP180MX
C_IN2: MURATA GRM32ER61C226KE20L
C_OUT1, C_OUT4: MURATA GRM31CR60J107ME39L
C_OUT2, C_OUT3: SANYO 2R5TPE330M9
DB1, DB2: CENTRAL SEMI CMDSH-4ETR
L1, L2: WÜRTH 7443330047
M1, M2: INFINEON BSC0911ND
Note: When operating with the power V_IN supply below 5.5V, this application requires the 5V to 5.5V external supply
to be present at EXTV_CC in order to maintain DRV_CC, INTV_CC and V_IN pin voltages needed for the IC to function
properly. The EXTV_CC supply is optional when the power V_IN supply is at or above 5.5V.
Power input voltage range of this application cannot be generalized for other frequency and/or output voltage. Each
application that needs a power input voltage different from the V_IN pin voltage shall be tested individually for margin
of range in which the switching nodes (SW1, SW2) phase-lock to the clock output (CLKOUT)
Figure 19. 3.3V to 14V Power Input, 1.2V/20A and 0.8V to 1.2V/20A (V_OUT2: EXTV_REF2 = 1:1)
Dual Output, 300kHz, R_SENSE, Step-Down Converter (with Externally-Available 5V to 5.5V Supply)
For more information www.linear.com/3838-2
38382f
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