TJ7660N

HTC TJ7660 is a monolithic CMOS power supply circuit that offers unique performance advantages over previously available devices. The TJ7660 converts input voltages in the range of +1.5V to +10.0V from positive to negative, generating complementary output voltages of -1.5V to -10.0V. Only two non-critical external capacitors are required to implement the charge pump and charge storage functions. The TJ7660 can also be connected as a voltage multiplier, producing output voltages up to +18.6V with a +10V input. The chip integrates an on-chip series DC power supply regulator, RC oscillator, voltage level translator, and four output power MOS switches. A unique logic element detects the most negative voltage in the device and ensures that the source-substrate junctions of the output N-channel switches are not forward-biased, guaranteeing latch-up free operation. At no load, with a 5.0V input supply voltage, the oscillator runs at a nominal frequency of 10kHz. This frequency can be reduced by adding an external capacitor to the OSC pin, or the oscillator can be driven by an external clock. The LV pin can be connected to ground to bypass the internal series regulator for improved low-voltage operation. At medium to high voltages (+3.5V to +10.0V for the TJ7660), the LV pin should be left floating to prevent device latch-up.

Applications

• On-board negative supply for dynamic RAM
• Local microprocessor (8080-type) negative supply
• Low-cost negative supply
• Data acquisition systems

Key features

• Simple conversion of +5V logic supply to ±5V supply
• Simple voltage multiplication (VOUT = (-) nVIN)
• Typical open-circuit voltage conversion efficiency: 99.9%
• Typical power efficiency: 98%
• Wide operating voltage range — TJ7660: 1.5V to 10.0V
• Easy to use — only 2 external non-critical passive components required
• No external diodes required across full temperature and voltage range
• Moisture Sensitivity Level 3