19-0329; Rev 0; 12/94 EVFAOLLULAOTWIOSNDKAITTAMSAHNEUEATL
High-Accuracy, Low-Dropout Linear Regulators
MAX687/MAX688/M...
19-0329; Rev 0; 12/94 EVFAOLLULAOTWIOSNDKAITTAMSAHNEUEATL
High-Accuracy, Low-Dropout Linear Regulators
MAX687/MAX688/MAX689
_______________General Description
The MAX687/MAX688/MAX689 low-dropout linear regulators operate with an input-to-output
voltage differential limited only by an external PNP transistor. Outputs are fixed at 3.3V (MAX687/MAX688) or 3.0V (MAX689). The only external components required are a PNP pass transistor and output, compensation, and bypass
capacitors. Base drive to the external transistor is at least 10mA, permitting output currents to exceed 1A when using high-gain transistors (β > 100). Output current limiting is implemented by limiting the external transistor’s base current. Output
voltage monitoring and shutdown functions are included.
The 3.3V MAX687 automatically shuts down whenever the output
voltage drops below 2.96V. An internal power-fail comparator also monitors the output and provides an early warning of low output
voltage before the device...