LTC1700 No RSENSE Synchronous Step-Up DC/DC Controller

The LTC®1700 is a current mode synchronous step-up DC/DC controller that drives external N-channel and P-channel power MOSFETs using a constant frequency PWM architecture. Current limiting is provided by sensing the voltage drop across the main MOSFET, eliminating the need of a sense resistor. This No RSENSETM technique helps the LTC1700 maintain high efficiency at heavy loads while Burst Mode operation ensures high efficiency at light loads, thus providing high efficiencies over a wide range of load currents.

The LTC1700 operates at a minimum input voltage as low as 0.9V. The device boasts a ±1.5% output voltage accuracy and consumes only 200µA of quiescent current. In shutdown, it only draws 10µA.

To prevent inductor current runaway, the duty cycle is limited to 90%. Overvoltage protection is also provided which shuts both the external MOSFETs off when tripped.

High constant operating frequency of 530kHz allows the use of small inductors and output capacitors. The LTC1700 can also be synchronized between 400kHz to 750kHz. Burst Mode operation is inhibited when the device is externally clocked or when the SYNC/MODE pin is pulled low to reduce noise and RF interference

产品特点 Features

High Efficiency: Up to 95%
No Current Sense Resistor Required
Constant Frequency 530kHz Operation Allows Small Size, Surface Mount Inductors
OPTI-LOOP® Compensation Minimizes COUT
Selectable Burst Mode® Operation
Minimum Start-Up Voltage as Low as 0.9V
Synchronizable Between 400kHz and 750kHz
Micropower Shutdown: 10µA
Current Mode Operation for Excellent Line and Load Transient Response
Soft-Start Reduces Supply Current Transients
1.5% Output Voltage Accuracy
Uses Low Value, Small Size, Surface Mount Inductors
Available in 10-Lead MSOP Package

应用

Cellular Telephones
Wireless Modems
RF Communications
2.5V to 3.3V, 2.5V to 5V Converters
Battery-Powered Equipment
Telecom/Network Systems

典型应用图

参数

LTC1700 订购信息和价格参考Package Variations and Pricing

器件型号	封装	引脚	温度	价格 (以 1 ~ 99 片为批量)	价格 (以 1000 片为批量) *
LTC1700EMS	MSOP	10	E	$3.07	$2.60
LTC1700EMS#PBF	MSOP	10	E	$3.07	$2.60
LTC1700EMS#TR	MSOP	10	E		$2.66
LTC1700EMS#TRPBF	MSOP	10	E		$2.66

LTC1700 数据手册及相关资料下载

数据手册(英文) : LTC1700 - No RSENSE Synchronous Step-Up DC/DC Controller.PDF
设计要点 (英文) : DN280 - Tiny and Efficient Boost Converter Generates 5V at 3A from 3.3V Bus.PDF
可靠性数据 : R419 Reliability Data .PDF