UC3845ADTR

UC1842A, UC1843A, UC1844A, UC1845A UC2842A, UC2843A, UC2844A, UC2845A UC3842A, UC3843A, UC3844A, UC3845A SLUS224G – SEPTEMBER 1994 – REVISED JULY 2022 UCx84xA Current-Mode PWM Controller 1 Features 3 Description • • • • • • • • • • • • The UCx84xA family of control devices is a pin-for-pin compatible improved version of the UCx84x family. Providing the necessary features to control currentmode or switched-mode power supplies, this family of devices has many improved features: startup current is less than 0.5 mA, oscillator discharge is trimmed to 8.3 mA, and during UVLO, the output stage can sink at least 10 mA at less than 1.2 V for VCC over 5 V. Optimized for Off-Line and DC-DC Converters Low Start-Up Current (< 0.5 mA) Trimmed Oscillator Discharge Current Automatic Feedforward Compensation Pulse-by-Pulse Current Limiting Enhanced Load Response Characteristics Undervoltage Lockout With Hysteresis Double Pulse Suppression High-Current Totem Pole Output Internally-Trimmed Bandgap Reference Up to 500-kHz Operation Create a Custom Design Using the UCx84xA With the WEBENCH® Power Designer Device Information(1) PART NUMBER PACKAGE BODY SIZE (NOM) UC1842A, UC1843A, UC1844A, UC1845A CDIP (8) 6.67 mm × 9.60 mm LCCC (20) 8.89 mm × 8.89 mm 2 Applications UC2843A PLCC (20) 8.96 mm × 8.96 mm • • • • • UC2842A, UC2843A, UC2844A, UC2845A, UC3842A, UC3843A, UC3844A, UC3845A PDIP (8) 6.35 mm × 9.81 mm SOIC (8) 3.91 mm × 4.90 mm SOIC (14) 3.91 mm × 8.65 mm SOIC (16) 7.50 mm × 10.30 mm Switch Mode Power Supplies (SMPS) DC-DC Converters Power Modules Industrial PSU Battery Operated PSU (1) For all available packages, see the orderable addendum at the end of the data sheet. Device Comparison Table UVLO ON UVLO OFF MAX DUTY CYCLE UC1842A 16 V 10 V