max843

Supply Voltage, VINto GND...........................................-0.3V to 10.5V
VNEGOUTto GND...........................................................-10.5V to 0.3V
VINto VNEGOUT................................................................0.3V to 21V
VOUTto GND (Note 1)................................................VNEGOUTto 0.3V
V SHDNto GND.....................................................-0.3V to (VIN+ 0.3V)
Continuous Power Dissipation (TA= +70°C)
SO (derate 5.88mW/°C above +70°C)....................................471mW

Operating Temperature Ranges
MAX84_I_ _A.............................................................-25°C to +85°C
MAX84_E_ _A............................................................-40°C to +85°C
Storage Temperature Range...................................-65°C to +150°C
Lead Temperature (soldering, 10sec)....................................+300°C

The max843 low-noise, inverting charge-pump power supplies are ideal for biasing GaAsFETs in cellular telephone transmitter amplifiers. max843 operate with inputs down to 2.5V. The MAX840 offers both a -2V preset output and a -0.5V to -9.4Vadjustable output.

The max843 use an external positive control voltage to set the negative output voltage. Input voltage range for all the devices is 2.5V to 10V, and output current is 4mA with VIN> 2.7V. These circuits max843 can operate with small capacitors, as low as 0.22µF.An internal linear regulator reduces the MAX840's out- put voltage ripple to 1mVp-p. With a well-filtered control voltage (VCTRL), the MAX843/MAX844 also achieve less than 1mVp-p typical output ripple. Supply current is 750µA, and reduces to less than 1µA in shutdown (MAX840/MAX843). The MAX844's unregulated output is active in shutdown, with the charge pump switching at 20kHz. It provides a low-power LCD supply.