L6730C Adjustable step-down controller with synchronous rectification

The controller is an integrated circuit realized in BCD5 (BiCMOS-DMOS, version 5) fabrication that provides complete control logic and protection for high performance step-down DC-DC and niPOL converters.

It is designed to drive N-Channel MOSFETs in a synchronous rectified buck topology. The output voltage of the converter can be precisely regulated down to 600mV with a maximum tolerance of ±0.8% or to 1.2V, when one of the internal references is used. It is also possible to use an external reference from 0V to 2.5V. The input voltage can range from 1.8V to 14V, while the supply voltage can range from 4.5V to 14V. High peak current gate drivers provide for fast switching to the external power section and the output current can be in excess of 20A, depending on the number of the external MOSFETs used. The PWM duty cycle can range from 0% to 100% with a minimum on-time (TON, MIN) lower than 100ns making possible conversions with very low duty cycle and very high switching frequency.

The device provides voltage-mode control. It includes a 400KHz free-running oscillator that is adjustable from 100KHz to 1MHz. The error amplifier features a 10MHz gain-bandwidth-product and 5V/µs slew-rate that permits to realize high converter bandwidth for fast transient response. The device monitors the current by using the RDS(on) of both the high-side and low-side MOSFET(s), eliminating the need for a current sensing resistor and guaranteeing an effective over-current-protection in all the application conditions. When necessary, two different current limit protections can be externally set through two external resistors. A leading edge adjustable blanking time is also available to avoid false over-current-protection (OCP) interventions in every application condition. It is possible to select the HICCUP mode or the constant current protection (L6730D) after the soft-start phase.

During the soft-start phase a constant current protection is provided. It is possible to select (before the device turn-on) the sink-source or the source-only mode capability by acting on a multifunction pin (L6730C). The L6730C disables the sink mode capability during the soft-start in order to allow a proper start-up also in pre-biased output voltage conditions. The L6730D can always sink current and so it can be used to supply the DDR Memory BUS termination. Other features are Master-Slave synchronization (with 180° phase shift), Power-Good with adjustable delay, over-voltage-protection, feed-back disconnection, selectable UVLO threshold (5V and 12V Bus) and thermal shutdown. The HTSSOP20 package allows the realization of really compact DC/DC converters.

技术特性

Input voltage range from 1.8V to 14V
Supply voltage range from 4.5V to 14V
Adjustable output voltage down to 0.6V with ±0.8% accuracy over line voltage and temperature (0˚C~125˚C)
Fixed frequency voltage mode control
TON lower than 100ns
0% to 100% duty cycle
Selectable 0.6V or 1.2V internal voltage reference
External input voltage reference
Soft-start and inhibit
High current embedded drivers
Predictive anti-crossconduction control
Selectable UVLO threshold (5V or 12V bus)
Programmable high-side and low-side RDS(on) sense over-current-protection
Switching frequency programmable from 100KHz to 1MHz
Master/slave synchronization with 180˚ phase shift
Pre-bias start up capability (L6730C)
Selectable source/sink or source only capability after soft-start (L6730C)
Selectable constant current or hiccup mode overcurrent protection after soft-start (L6730D)
Power good output with programmable delay
Over voltage protection with selectable latched/not-latched mode
Thermal shut-down
Package: HTSSOP20, QFN4x4 24L

功能框图

L6730C 订购信息

订购型号	产品状态	美金价格	数量	封装	包装形式	温度范围	材料声明
L6730CQTR	Evaluation		1000	VFQFPN 24 4x4x1.0	Tape And Reel
L6730CQ	Evaluation		1000	VFQFPN 24 4x4x1.0	Tube

DATASHEET

描述	版本	大小
L6730C : Adjustable step-down controller with synchronous rectification	2	1502KB