Texas Instruments UC28023 UC28025 Data Sheet

查询UC28023DW供应商

SLUS557B − MARCH 2003 − REVISED APRIL 2004

FEATURES DESCRIPTION Peak Current Mode, Average Current Mode,

The UC28023 and UC28025 are fixed-frequency

or Voltage Mode (with Feed-Forward) Control

PWM controllers optimized for high-frequency

Methods

switched-mode power supply applications. The

Practical Operation Up to 1 MHz UC28023 is a single output PWM for single-ended

topologies while the UC28025 offers dual

50-ns Propagation Delay to Output

alternating outputs for double-ended and full

±1.5-A Peak Totem Pole Outputs

bridge topologies.

9-V to 30-V Nominal Operational Voltage

Targeted for cost effective solutions with minimal

Range

external components, UC2802x include an

Wide Bandwidth Error Amplifier

oscillator, a temperature compensated reference,

Fully Latched Logic with Double Pulse

a wide band width error amplifier, a high-speed

Suppression

current-sense comparator and high-current

Pulse-by-Pulse Current Limiting active-high totem-pole outputs to directly drive

external MOSFETs.

Programmable Maximum Duty Cycle Control Under−Voltage Lockout with Hysteresis Protection circuitry includes a current limit

comparator with a 1-V threshold, a TTL

Trimmed 5.1-V Reference with UVLO

compatible shutdown port, and a soft-start pin

Same Functionality as UC3823 and UC3825

which will double as a maximum duty cycle clamp. The logic is fully latched to provide jitter free

APPLICATIONS

operation and prohibit multiple pulses at an Off-Line and DC/DC Power Supplies output. An undervoltage lockout section with 800 m V of hysteresis assures low start-up

Converters Using Voltage Mode, Peak

current. During undervoltage lockout, the outputs

Current Mode, or Average Current Mode

are high impedance. Particular care was given to

Control Methods

minimizing propagation delays through the

Single-Ended or Two-Switch Topology

comparators and logic circuitry while maximizing

Designs

bandwidth and slew rate of the error amplifier. Devices are available in the industrial temperature range of −40°C to 105°C. Package offerings are 16-pin SOICW (DW), or 16-pin PDIP (N) packages.

ORDERING INFORMATION

OUTPUT EXTERNAL CURRENT PACKAGED DEVICES

TA = TJ

CONFIGURATION LIMIT REFERENCE PDIP-16 (N) SOICW−16 (DW) Single Yes UC28023N UC28023DW

−40°C to 105°C

Dual Alternating No UC28025N UC28025DW

(1) The DW package are also available taped and reeled. Add an R suffix to the device type (i.e., UC28023DWR (2,000 devices per reel).

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