L6732: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 600 mV with a maximum tolerance of ±0.8 % and it is also possible to use an external reference from 0 V to 2.5 V.

The input voltage can range from 1.8 V to 14 V, while the supply voltage can range from 4.5 V to 14 V. High peak current gate drivers provide for fast switching to the external power section, and the output current can be in excess of 20 A. The PWM duty cycle can range from 0 % to 100 % with a minimum on-time (TON, MIN) lower than 100 ns making possible conversions with very low duty cycle at high switching frequency. The device provides voltage-mode control that includes a selectable frequency oscillator (250 kHz or 500 kHz).

The error amplifier features a 10 MHz gain-bandwidth-product and 5 V/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.

During the soft-start phase a constant current protection is provided while after the soft-start the device enters in hiccup mode in case of over-current. During the soft-start, the sink mode capability is disabled in order to allow a proper start-up also in pre-biased output voltage conditions. After the soft-start the device can sink current. Other features are power good, master/slave synchronization (with 180° phase shift), over-voltage-protection, feed-back disconnection and thermal shutdown. The HTSSOP16 package allows the realization of really compact DC/DC converters.

Key Features

  • Predictive anti-cross conduction control
  • High current embedded drivers
  • Selectable switching frequency 250KHz/500KHz
  • Programmable high-side and low-side RDS(on) sense over-current-protection
  • Power good output
  • Pre-bias start up capability
  • Over voltage protection
  • Master/slave synchronization with 180˚ phase shift
  • Thermal shut-down
  • External input voltage reference
  • 0% to 100% duty cycle
  • Input voltage range from 1.8V to 14V
  • Adjustable output voltage down to 0.6V with ±0.8% accuracy over line voltage and temperature (0˚C~125˚C)
  • Supply voltage range from 4.5V to 14V
  • TON lower than 100ns
  • Soft-start and inhibit
  • Fixed frequency voltage mode control
  • Package: HTSSOP16
Product Specifications
DescriptionVersionSize
DS4562: Adjustable step-down controller with synchronous rectification6.1889 KB
Brochures
DescriptionVersionSize
Brochure Power management guide05.20164 MB
Sample & Buy
Part NumberPackagePacking TypeUnit Price (US$) *QuantityECCN (EU)ECCN (US)Country of Origin
L6732HTSSOP16Tube--NECEAR99-
L6732TRHTSSOP16Tape And Reel--NECEAR99-
Quality & Reliability
Part NumberPackageGradeRoHS Compliance GradeMaterial Declaration**
L6732HTSSOP16IndustrialEcopack2
L6732TRHTSSOP16IndustrialEcopack2
Adjustable step-down controller with synchronous rectification L6732
circuit_diagram_11934_thumbnail.png L6732
Very low drop voltage regulators with inhibit KFXX