LTC3355_15 Datasheet, PDF (20/20 Pages) Linear Technology – 20V 1A Buck DC/DC with Integrated SCAP Charger and Backup Regulator

LTC3355
TYPICAL APPLICATION
NiMH Trickle Charger and Ride-Through Backup Supply
R_S*
V_IN
5V
0.27Ω
C_IN
C_VIN*
C_CAP ^{5 VIN}
10µF
10µF
1µF _{6 VINM5}
4 ^VINS
R7
931k
1 PFI
R8
200k
SW1 ₇
PFO
BUCK _{VOUT 15}
LTC3355
FB 2
V_{CAP 14}
L1
4.7µH
D1
R1
316k
V_OUT
3.3V
47µF 50mA (MAX)
D2
R2
100k
200Ω
MICROPROCESSOR
24 HOURS
*OPTIONAL
10 PFOB
13 RSTB
SW2
16
9 CPGOOD
BOOST
17
8 EN_CHG
CFB 11
3 MODE
INTV_CC
I_CHG
V_CBST 19
I_BSTPK
18
12
20
C1
R5
R6
1µF 604k
909k
L2 3.3µH
+
R3
499k
1.4V
NiMH
2000mAhr
R_C
154k
C_C
220pF
3355 TA03
R4
499k
RELATED PARTS
PART
NUMBER
LTC3225/
LTC3225-1
LTC3226
LT3485
LTC3625/
LTC3625-1
LT^®3750
LT3751
LTC4425
DESCRIPTION
150mA Supercapacitor Charger
2-Cell Supercapacitor Charger with Backup
PowerPath™ Controller
Photoflash Capacitor Chargers with Output
Voltage Monitor and Integrated IGBT Drive
1A High Efficiency 2-Cell Supercapacitor
Charger with Automatic Cell Balancing
Capacitor Charger Controller
High Voltage Capacitor Charger Controller with
Regulation
Supercapacitor Charger with Current Limited
Ideal Diode
COMMENTS
Low Noise, Constant Frequency Charging of Two Series Supercapacitors. Automatic
Cell Balancing Prevents Capacitor Overvoltage During Charging. Programmable Charge
Current (Up to 150mA). 2mm × 3mm DFN Package
1×/2× Multimode Charge Pump Supercapacitor Charger Ideal Diode Main PowerPath™
Controller, Internal 2A LDO Back-Up Supply, 16-Lead (3mm × 3mm) QFN Package
Integrated IGBT Driver; Voltage Output Monitor; Uses Small Transformers: 5.8mm
× 5.8mm × 3mm. Operates from Two AA Batteries, Single Cell Li-Ion or Any Supply
from 1.8V Up to 10V. No Output Voltage Divider Needed; No External Schottky Diode
Required. Charges Any Size Photoflash Capacitor; 10-Lead (3mm × 3mm) DFN Package
High Efficiency Step-Up/Step-Down Charging of Two Series Supercapacitors. Automatic
Cell Balancing Prevents Capacitor Overvoltage During Charging. Programmable
Charging Current Up to 500mA (Single Inductor), 1A (Dual Inductor). V_IN = 2.7V to
5.5V, Low No-Load Quiescent Current: 23µA. 12-lead 3mm × 4mm DFN Package
Charges Any Size Capacitor; Easily Adjustable Output Voltage. Drives High Current
NMOS FETs; Primary-Side Sense—No Output Voltage Divider Necessary. Wide Input
Range: 3V to 24V; Drives Gate to V_CC – 2V. 10-Lead MS Package
Charges Any Size Capacitor; Low Noise Output in Voltage Regulation Mode. Stable
Operation Under a No-Load Condition; Integrated 2A MOSFET Gate Driver with
Rail-to-Rail Operation for V_CC ≤ 8V. Wide Input V_CC Voltage Range
(5V to 24V). 20-Pin QFN 4mm × 5mm and 20-Lead TSSOP Packages
Constant-Current/Constant-Voltage Linear Charger for 2-cell Series Supercapacitor
Stack. V_IN: Li-Ion/Polymer Battery, a USB Port, or a 2.7V to 5.5V Current-Limited
Supply. 2A Charge Current, Auto Cell Balancing, 20µA Quiescent Current, Shutdown
Current <2µA. Low Profile 12-Pin 3mm × 3mm DFN or a 12-Lead MSOP Package
20 Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 950_Fo3_r5_m-7_o4_re1_i7_{nformation www.linear.com/LTC3355}
[phone] ^● FAX: [phone] ^● www.linear.com/LTC3355
3355fb
LT 0415 REV B • PRINTED IN USA
 LINEAR TECHNOLOGY CORPORATION 2014