Datasheet LTC3703 (Analog Devices)

LTC3703 100V Synchronous Switching Regulator Controller
FeaTures DescripTion
n
High Voltage Operation: Up to 100V
The LTC®3703 is a synchronous step-down switching n
Large 1Ω Gate Drivers
regulator controller that can directly step down voltages n
No Current Sense Resistor Required
from up to 100V, making it ideal for telecom and automo- n
Step-Up or Step-Down DC/DC Converter
tive applications. The LTC3703 drives external N-channel n Dual N-Channel MOSFET Synchronous Drive MOSFETs using a constant frequency (up to 600kHz), n Excellent Line and Load Transient Response voltage mode architecture. n Programmable Constant Frequency: 100kHz to A precise internal reference provides 1% DC accuracy. 600kHz A high bandwidth error amplifier and patented line feed- n ±1% Reference Accuracy forward compensation provide very fast line and load n Synchronizable up to 600kHz transient response. Strong 1Ω gate drivers allow the n Selectable Pulse-Skip Mode Operation LTC3703 to drive multiple MOSFETs for higher current ap- n Low Shutdown Current: 50µA Typ plications. The operating frequency is user programmable n Programmable Current Limit from 100kHz to 600kHz and can also be synchronized to n Undervoltage Lockout an external clock for noise-sensitive applications. Cur- n Programmable Soft-Start rent limit is programmable with an external resistor and n 16-Pin Narrow SSOP and 28-Pin SSOP Packages utilizes the voltage drop across the synchronous MOSFET
applicaTions
to eliminate the need for a current sense resistor. For ap- plications requiring up to 60V operation with logic-level n 48V Telecom and Base Station Power Supplies MOSFETS, refer to the LTC3703-5 data sheet. n Networking Equipment, Servers
PARAMETER LTC3703-5 LTC3703
n Automotive and Industrial Control Maximum VIN 60V 100V L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and MOSFET Gate Drive 4.5V to 15V 9.3V to 15V ThinSOT and No RSENSE are trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Protected by U.S. Patents, including 5408150, VCC UV+ 3.7V 8.7V 5055767, 6677210, 5847554, 5481178, 6304066, 6580258. VCC UV– 3.1V 6.2V
Typical applicaTion
VCC 9.3V TO 15V + 22µF VIN
Efficiency vs Load Current
25V BAS19 15V TO 100V 100 MODE/SYNC VIN + 30k 68µF fSET BOOST VIN = 25V 10k LTC3703 Si7456DP 95 VIN = 50V COMP TG 0.1µF 1000pF 470pF 8µH VOUT VIN = 75V FB SW 12V 15k 5A + 90 I 270µF 8.06k MAX VCC 16V 1% 10Ω EFFICIENCY (%) INV DRVCC 0.1µF 85 Si7456DP RUN/SS BG 113k MBR1100 100Ω 10µF 1% GND BGRTN 80 0 1 2 3 4 5 2200pF 1µF LOAD (A) 3703 F01b 3703 F01
Figure 1. High Efficiency High Voltage Step-Down Converter
3703fc 1 Document Outline Features Description Applications Typical Application Absolute Maximum Ratings Pin Configuration Order Information Electrical Characteristics Typical Performance Characteristics Pin Functions Functional Diagram Operation Applications Information Typical Applications Package Description Revision History Typical Application Related Parts