UCC3895 是一款相移 PWM 控制器,它通过相移切换一个半桥相对于另一半桥来实现对全桥功率级的控制。该器件支持恒定频率脉冲宽度调制和谐振零电压开关,可在高频下提供高效率。该器件既可用作电压模式控制器,也可用作电流模式控制器。
UCC3895 在保留了 UC3875/6/7/8 系列和 UC3879 的功能的同时,还改进了该控制器系列,使其具有增强的控制逻辑、自适应延迟设置和关断 功能 等附加功能。由于该器件采用 BCDMOS 工艺制造,因此与双极型同类器件相比,它的工作电流要小得多。UCC3895 的最大时钟频率为 1MHz。
器件型号 | 封装 | 封装尺寸(标称值) |
---|---|---|
UCCx895 | CDIP (20) | 24.20mm × 6.92mm |
LCCC (20 | 8.89mm × 8.89mm | |
SOIC (20) | 12.80mm × 7.50mm | |
PDIP (20) | 24.33mm × 6.35mm | |
TSSOP (20) | 6.50mm × 4.40mm | |
PLCC (20) | 8.96mm × 8.96mm |
Changes from P Revision (June 2013) to Q Revision
Changes from O Revision (April 2010) to P Revision
Changes from N Revision (May 2009) to O Revision
PIN | I/O | DESCRIPTION | |
---|---|---|---|
NAME | NO. | ||
ADS | 11 | I | The adaptive-delay-set pin sets the ratio between the maximum and minimum programmed output delay dead time. |
CS | 12 | I | Current sense input for cycle-by-cycle current limiting and for over-current comparator. |
CT | 7 | I | Oscillator timing capacitor for programming the switching frequency. The UCC3895 oscillator charges CT via a programmed current. |
DELAB | 9 | I | The delay-programming between complementary-outputs pin, DELAB, programs the dead time between switching of output A and output B. |
DELCD | 10 | I | The delay-programming between complementary-outputs pin, DELCD, programs the dead time between switching of output C and output D. |
EAOUT | 2 | I/O | Error amplifier output. |
EAP | 20 | I | Non-inverting input to the error amplifier. Keep below 3.6 V for proper operation. |
EAN | 1 | I | Inverting input to the error amplifier. Keep below 3.6 V for proper operation. |
GND | 5 | — | Chip ground for all circuits except the output stages. |
OUTA | 18 | O | The four outputs are 100-mA complementary MOS drivers, and are optimized to drive FET driver circuits such as UCC27714 or gate drive transformers. |
OUTB | 17 | O | |
OUTC | 14 | O | |
OUTD | 13 | O | |
PGND | 16 | — | Output stage ground. |
RAMP | 3 | I | Inverting input of the PWM comparator. |
REF | 4 | O | 5-V, ±1.2%, 5-mA voltage reference. For best performance, bypass with a 0.1-μF low ESR, low ESL capacitor to ground. Do not use more than 4.7 μF of total capacitance on this pin. |
RT | 8 | I | Oscillator timing resistor for programming the switching frequency. |
SS/DISB | 19 | I | Soft-start and disable pin which combines the two independent functions. |
SYNC | 6 | I/O | The oscillator synchronization pin is bidirectional. |
VDD | 15 | I | The power supply input pin, VDD, must be bypassed with a minimum of a 1-μF low ESR, low ESL capacitor to ground. The addition of a 10-μF low ESR, low ESL between VDD and PGND is recommended. |