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

LTC3838-2
TYPICAL APPLICATION
7V to 14V Input, 5V/5A and 2.5V to 5V/5A (V_OUT2: EXTV_REF2 = 2:1)/5A Dual Output, 2MHz, R_SENSE,
Step-Down Converter with EXTV_CC Tied to 5V Output
V_IN
7V TO 14V _{+ CIN1}
39µF
C_IN2
10µF
×3
2.2Ω
1µF
10Ω
10Ω
1nF
0.1µF
LTC3838-2
V_IN
SENSE1^–
SENSE2^–
SENSE1⁺
SENSE2⁺
10Ω
1nF _10Ω
0.1µF
R_S1
L1
MT1
V_OUT1 0.004Ω 0.8µH
5V
7A
C_OUT1
47µF
×2
MB1
DB1
2.2Ω
1µF
BOOST1
TG1
SW1
4.7µF
DRV_CC1
INTV_CC
BG1
BOOST2
TG2
SW2
DRV_CC2
EXTV_CC
BG2
DB2
V_OUT1
MT2
L2
R_S2
0.8µH _0.004Ω
V_OUT2
2.5V TO 5V
7A
C_OUT2
47µF
MB2
×2
73.2k
C_FF1
47pF
PGND
EXTV_REF2
V_REF2+
1.25V TO 2.5V
20k
V_OUTSENSE1+ VDFB2+
10k
20k
10k
C_FF2
V_REF2– ^150pF
100k
V_{OUTSENSE1–}
PGOOD1 _PGOOD1
0.01µF
V_DFB2–
PGOOD2 ^PGOOD2
0.01µF
TRACK/SS1 TRACK/SS2
22pF
68pF
ITH1
330pF
24.9k
ITH2
900pF
13k
100k
18.7k
DTR1
RT
SGND
RUN1
DTR2
PHASMD
MODE/PLLIN
CLKOUT
RUN2
38382 TA02
C_IN1: SANYO 16SVP180MX
C_IN2: MURATA GRM32ER61C226KE20L
C_OUT1, C_OUT2: MURATA GRM43ER60J476ME01L
DB1, DB2: CENTRAL CMDSH-3
L1, L2: COILCRAFT XAL5030-801MEB
MT1, MB1, MT2, MB2: VISHAY SI7114ADN
RELATED PARTS
PART NUMBER
DESCRIPTION
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Fast Controlled On-Time, High Frequency Synchronous
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LTC3850-2
Controller, R_SENSE or DCR Current Sensing
COMMENTS
200kHz to 2MHz Operating Frequency, 4.5V ≤ V_IN ≤ 38V,
0.6V ≤ V_OUT ≤ 5.5V, 3mm × 4mm QFN-20, TSSOP-20
200kHz to 2MHz Operating Frequency, 4.5V ≤ V_IN ≤ 38V,
0.6V ≤ V_OUT ≤ 5.5V, 5mm × 7mm QFN-38, TSSOP-38
200kHz to 2MHz Operating Frequency, 4.5V ≤ V_IN ≤ 38V,
0.6V ≤ V_OUT ≤ 5.5V, 5mm × 5mm QFN-32
I²C/PMBus Interface with EEPROM and 16-Bit ADC, V_IN Up to 24V,
0.5V ≤ V_OUT ≤ 5.5V, Analog Control Loop
PLL Fixed 250kHz to 750kHz Frequency, 4V ≤ V_IN ≤ 38V,
V_OUT3 Up to 12.5V
PLL Fixed Frequency 250kHz to 770kHz, 4.5V ≤ V_IN ≤ 38V,
0.8V ≤ V_OUT ≤ 12V
PLL Fixed 250kHz to 770kHz Frequency, 4.5V ≤ V_IN ≤ 38V,
0.8V ≤ V_OUT ≤ 5V
Operates with Power Blocks, DRMOS Devices or External Drivers/
MOSFETs, 3V ≤ V_IN ≤ 24V, t_ON(MIN) = 20ns
PLL Fixed 250kHz to 780kHz Frequency, 4V ≤ V_IN ≤ 30V,
0.8V ≤ V_OUT ≤ 5.25V
38382f
56 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 950_F3_o5_r-_m7_o4_r1_e7_{information www.linear.com/3838-2}
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LT 0213 • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2013