TC1142

Supply Voltage (V_IN) with C_OUT Connected ..........6.5V
CCLK Voltage................................-0.3V to (V+ + 0.3V)
Power Dissipation............................................320mW
Operating Temperature Range
           8-Pin MSOP .................................-40to +85
Storage Temperature Range ..............-65 to +160

*Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These
are stress ratings only and functional operation of the device at these or any other conditions above those indicated in the operation sections of the specifications is not implied. Exposure to Absolute Maximum Rating conditions for
extended periods may affect device reliability.

The TC1142 generates a regulated negative voltage from -3V to -5V at 20mA from an input of 2.5V to 5.5V, using only three external capacitors. Other boost/buck switching regulators must use an inductor, which is larger and radiates EMI. An internal voltage comparator inhibits the charge pump when V_OUT is more negative than the regulated value (per the ordering option). The values of flying capacitors C1 and C2 are chosen to be less than C_OUT in order to reduce the ripple generated from regulating V_OUT in this manner. The TC1142 also can be used as a -1x buck regulator by omitting C2, and connecting the C2 pin to V_OUT.

The part goes into shutdown when the CCLK input is driven low. When in shutdown mode, the part draws a
maximum of 1µA. When CCLK is pulled high, the part runs from the internal 200kHz oscillator. The device
may be run with an external clock, provided the frequency is greater than 3kHz and less than 500kHz.

The TC1142 comes in a space-saving MSOP package.