UCD8620

The UCD8220 and UCD8620 are members of the UCD8K family of analog pulse-width modulator devices to be used in digitally managed power supplies using a microcontroller or the TMS320™ DSP family.

UCD8220 and UCD8620 are double-ended PWM controllers configured with push-pull drive logic. The UCD8620 has a 110-V high-voltage startup circuit which can directly start up the controller from a 48-V telecom input line.

UCD8220 and UCD8620 Systems using UCD8K devices close the PWM feedback loop with traditional analog methods, but the UCD8K controllers include circuitry to interpret a time-domain digital pulse train. The pulse train contains the operating frequency and maximum duty cycle limit which are used to control the power supply operation. This eases implementation of a converter with high level control features without the added complexity or possible PWM resolution limitations of closing the control loop in the discrete time domain.

The UCD8220 and UCD8620 can be configured for either peak current mode or voltage mode control. They provide a programmable current limit function and a digital output current limit flag which can be monitored by the host controller to set the current limit operation. For fast switching speeds, the output stages use the TrueDrive™ architecture, which delivers rated current of ±4 A into the gate of a MOSFET. Finally they also include a 3.3-V, 10-mA linear regulator to provide power to the digital controller or act as a reference in the system.

The UCD8K controller family is compatible with the standard 3.3-V I/O ports of UCD9K digital power controllers, DSPs, Microcontrollers, or ASICs and is offered in PowerPAD™ HTSSOP and QFN packages.