PT7A7511-15/7521-25/7531-35 P Supervisor Circuits Features Description Precision supply-voltage monitor The PT7A751X/752X/753X family micro-processor - 4.63V (PT7A7511, 7521, 7531) ( P) supervisory circuits are targeted to improve - 4.38V (PT7A7512, 7522, 7532) reliability and accuracy of power-supply circuitry in - 3.08V (PT7A7513, 7523, 7533) Ps systems. These devices reduce the complexity and - 2.93V (PT7A7514, 7524, 7534) number of components required to monitor power- - 2.63V (PT7A7515, 7525, 7535) supply and battery functions. 200ms reset pulse width The main functions are: Debounced TTL/CMOS-compatible manual- 1. Asserting reset output during power-up, power- reset input down and brownout conditions for P system. Independent watchdog timer 1.6sec time-out (not available for PT7A7531 - 7535) 2. Detecting power failure or low-battery Reset output signal: conditions with a 1.25V threshold detector. - Active-low only (PT7A7511 - 7515) 3. Watchdog functions (not for PT7A753x) - Active-high only (PT7A7521 - 7525) - Active-high and active-low (PT7A7531 - 7535) Applications Voltage monitor for power-fail or low battery Power-supply circuitry in P systems warning Guaranteed RESET/RESET valid at V =1.2V CC PT7A7511P-7515P PT7A7521P-7525P PT7A7531P-7535P PT7A7511W-7515W PT7A7521W-7525W PT7A7531W-7535W Pin Configuration 8-Pin PDIP/8-Pin SOIC 8-Pin PDIP/8-Pin SOIC 8-Pin PDIP/8-Pin SOIC 1 8 WDO 1 8 WDO 1 8 RESET MR MR MR 2 7 2 7 2 7 V RESET V RESET V RESET CC CC CC 3 6 WDI 3 6 WDI 3 6 NC GND GND GND 4 4 4 5 PFO 5 PFO 5 PFO PFI PFI PFI Top View PT7A7511W-7515W PT7A7521W-7525W PT7A7531W-7535W All trademarks are property of their respective owners. www.diodes.com 3/13/2017 2017-02-0003 PT0082-10 1 PT7A7511-15/7521-25/7531-35 Pin Description Pin Type Description Manual-Reset: triggers a reset pulse when pulled below 0.8V, active low. It has an internal 250A pull- MR I up current and be driven from a TTL or CMOS logic line as well as shorted to ground with a switch. V Power Supply Voltage. CC GND Ground Ground Reference for all signals. Power-Fail Voltage Monitor Input. When PFI is less than 1.25V, PFO goes low. Connect PFI to GND PFI I or Vcc when not used. Power-Fail Output: it gets low and sinks current when PFI is less than 1.25V otherwise PFO stays high. O PFO Watchdog Input: If WDI remains high or low for 1.6sec, the internal watchdog timer runs out and WDO goes low. Floating WDI or connecting WDI to a high-impedance three-state buffer disables the watchdog WDI I feature. The internal watchdog timer clears whenever reset is asserted. WDI is three-stated, or WDI sees a rising or falling edge. Reset Output pulses: low for 200ms when triggered, and stays low whenever Vcc is below the reset RESET O threshold. It remains low for 200ms after Vcc rises above the reset threshold or MR goes from low to high. A watchdog timeout will not trigger RESET unless WDO is connected to MR. Watchdog Output: pulls low when the internal watchdog timer finishes its 1.6sec count and does not go WDO high again until the watchdog is cleared. WDO also goes low during low-line conditions. Whenever Vcc is O below the reset threshold, WDO stays low however, unlike RESET, WDO does not have minimum pulse width. As soon as Vcc rises above the reset threshold, WDO goes high with no delay. RESET O The inverse of RESET, active high. Whenever RESET is high, RESET is low. Block Diagram Block Diagram of PT7A7511-7515/7521-7525 Watchdog Watchdog Timer WDI WDO Transition Detector V cc Timebase for Reset 250uA & Watchdog MR RESET Reset Generator (RESET) Vcc V RST PFI PFO 1.25V All trademarks are property of their respective owners. www.diodes.com 3/13/2017 2017-02-0003 PT0082-10 2