Regulator ICs 6-channel switching regulator controller BA9736KV The BA9736KV is a 6-channel controller that includes all of the circuits required to construct a switching regulator. The circuits on the chip include a triangular-wave generator, a reference voltage circuit, an error amplifier, a PWM comparator, a pseudo-totem-pole driver, and a variety of protection circuits. Applications VCR / cameras, digital still cameras, and other portable equipment Features 1) The totem-pole driver can directly drive power transistors, and the on current can be set to the rating current using an external resistor. 2) Miss-operation prevention circuit for low-voltage input. 3) Output cutoff circuit (timer latch type) for overload protection. 4) Channels 1 and 4 employ FETs, and have totem-pole drivers that rectify synchronously with a chopper. The duty offset of the chopper can be adjusted externally. Absolute maximum ratings (Ta = 25C) Recommended operating conditions (Ta = 25C) 432 5) For channel control, by making STB low level, all channels go off, and by making STB3 low level, channel 3 can be switched off independently. 6) Soft start is applied to all channels using an external capacitor, and is synchronized with the rising edges of STB and STB3. 7) VQFP64 package (0.5mm pitch). Regulator ICs BA9736KV Block diagram 433 Regulator ICs Pin descriptions 434 BA9736KV Regulator ICs BA9736KV Electrical characteristics (unless otherwise noted, Ta = 25C, VCC = 7.2V, fOSC = 700kHz and output voltage off) 435 Regulator ICs 436 BA9736KV Regulator ICs BA9736KV Measurement circuits 437 Regulator ICs 438 BA9736KV Regulator ICs BA9736KV 439 Regulator ICs Application example 440 BA9736KV Regulator ICs Operation notes (1) Set the dead-time input voltage to 0.73V or more. (2) Use short and wide wiring tracks for the power supply and ground to keep the mutual impedance as small as possible, and use inductors and capacitors to keep ripple to a minimum. (3) Set RDUTY so that the drive stage and the MOS drive stage for the synchronous rectifier channel are not on at the same time. (4) If you are not using the external trigger input (pin 13) for overload output cutoff, pull it up to VCC (pin 28). BA9736KV (5) Great care has been paid to the quality of this component. However, if the absolute maximum ratings for temperature and applied voltage are exceeded, the IC may be destroyed. Since it is not possible to predict whether it will be in short mode or open mode if the IC is destroyed, if there is a chance that the maximum ratings of the IC will be exceeded, use appropriate physical protective measures (fuses etc.). External dimensions (Units: mm) 441