The UCC3809 family of BCDMOS economy low power integrated circuits contains all the control and drive circuitry required for off-line and isolated DC-to-DC fixed frequency current mode switching power supplies with minimal external parts count. Internally implemented circuits include undervoltage lockout featuring startup current less than 100µA, a user accessible voltage reference, logic to ensure latched operation, a PWM comparator, and a totem pole output stage to sink or source peak current. The output stage, suitable for driving N-Channel MOSFETs, is low in the off state.

Oscillator frequency and maximum duty cycle are programmed with two resistors and a capacitor. The UCC3809 family also features full cycle soft start.

The family has UVLO thresholds and hysteresis levels for off-line and DC-to-DC systems as shown in the table to the left.

The UCC3809 and the UCC2809 are offered in the 8 pin SOIC (D), PDIP (N), TSSOP (PW), and MSOP (P) packages. The small TSSOP and MSOP packages make the device ideal for applications where board space and height are at a premium.

• User Programmable Soft Start With Active Low Shutdown
• User Programmable Maximum Duty Cycle
• Accessible 5V Reference
• Undervoltage Lockout
• Operation to 1MHz
• 0.4A Source/0.8A Sink FET Driver
• Low 100μA Startup Current

• Topology
• Boost, Buck, Flyback, Forward
• Duty cycle (Max) (%)
• 70
• Supply voltage (Max) (V)
• 19
• UVLO thresholds on/off (V)
• 10/8
• Features
• Adjustable Switching Frequency, Multi-topology, Soft Start
• Operating temperature range (C)
• 0 to 70
• Rating
• Catalog
• Frequency (Max) (kHz)
• 1000
• Gate drive (Typ) (A)
• 0.8

UCC3809-1的完整型号有：UCC3809D-1、UCC3809DTR-1、UCC3809P-1、UCC3809PTR-1，以下是这些产品的关键参数及官网采购报价：

UCC3809D-1，工作温度：0 to 70，封装：SOIC (D)-8，包装数量MPQ：75个，MSL 等级/回流焊峰值温度：Level-1-260C-UNLIM，引脚镀层/焊球材料：NIPDAU，TI官网UCC3809D-1的批量USD价格：1.072（1000+）

UCC3809DTR-1，工作温度：0 to 70，封装：SOIC (D)-8，包装数量MPQ：2500个，MSL 等级/回流焊峰值温度：Level-1-260C-UNLIM，引脚镀层/焊球材料：NIPDAU，TI官网UCC3809DTR-1的批量USD价格：.893（1000+）

UCC3809P-1，工作温度：0 to 70，封装：VSSOP (DGK)-8，包装数量MPQ：80个，MSL 等级/回流焊峰值温度：Level-2-260C-1 YEAR，引脚镀层/焊球材料：NIPDAUAG，TI官网UCC3809P-1的批量USD价格：1.072（1000+）

UCC3809PTR-1，工作温度：0 to 70，封装：VSSOP (DGK)-8，包装数量MPQ：2500个，MSL 等级/回流焊峰值温度：Level-2-260C-1 YEAR，引脚镀层/焊球材料：NIPDAUAG，TI官网UCC3809PTR-1的批量USD价格：.893（1000+）

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