SP706CU

SP705 EXAR | Alldatasheet

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June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation SP705-708/813L Low Power Microprocessor Supervisory Circuits n Precision Voltage Monitor: SP705/707/813L at 4.65V SP706/708 at 4.40V n RESET Pulse Width - 200ms n Independent Watchdog Timer - 1.6s Timeout (SP705/706/813L) n 60µA Maximum Supply Current n Debounced TTL/CMOS Manual Reset Input n RESET Asserted Down to VCC = 1.1V n Voltage Monitor for Power Failure or Low Battery Warning n Available in 8-pin PDIP, NSOIC, and µSOIC packages n Pin Compatible Enhancement to Industry Standard 705-708/813L Series n Functionally Compatible to Industry Standard 1232 Series DESCRIPTION… The SP705-708/813Lseries is a family of microprocessor (µP) supervisory circuits that integrate myriad components involved in discrete solutions which monitor power-supply and battery in µP and digital systems. The SP705-708/813Lseries will significantly improve system reliability and operational efficiency when compared to solutions obtained with discrete components. The features of the SP705-708/813Lseries include a watchdog timer, a µP reset, a Power Fail Comparator, and a manual-reset input. The SP705-708/813L series is ideal for applications in automotive systems, computers, controllers, and intelligent instruments. The SP705-708/813Lseries is an ideal solution for systems in which critical monitoring of the power supply to the µP and related digital components is demanded. Part RESET RESET Manual PFI Number Threshold Active RESET Watchdog Accuracy SP705 4.65 V LOW YES YES 4% SP706 4.40 V LOW YES YES 4% SP707 4.65 V LOW and HIGH YES NO 4% SP708 4.40 V LOW and HIGH YES NO 4% SP813L 4.65 V HIGH YES YES 4% Now available in Lead Free

June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation R E T E M A R A P . N I M .P Y T .X A M S T I N U S N O I T I D N O C V , e g n a R e g a t l o V g n i t a r e p O C C . 1 1 5.5 V I , t n e r r u C y l p p u S Y L P P U S 0 4 0 6 µA V = R M C C g n i t a o l F I D W , g n i t a o l F r o d l o h s e r h T t e s e R 0 5 . 4 5 2 . 4 5 6 . 4 0 4 . 4 5 7 . 4 0 5 . 4 V 2 e t o N , L 3 1 8 P S , 7 0 7 P S , 5 0 7 P S SP706, SP708, Note 2 s i s e r e t s y H d l o h s e r h T t e s e R 0 4 V m 2 e t o N t , h t d i W e s l u P t e s e R S R 0 4 1 0 0 2 0 8 2 s m 2 e t o N T E S E R e g a t l o V t u p t u O C 5 . 1 - 8 . 0 0 4 . 0 0 3 . 0 V 2 e t o N I E C R U O S 0 0 8 = µA I E C R U O S 4 = µ V , A C C V 1 . 1 = I K N I S A m 2 . 3 = Vcc = 1.1V, ISINK = 50 µA t , d o i r e P t u o e m i T g o d h c t a W D W 0 0 . 1 0 6 . 1 5 2 . 2 s L 3 1 8 P S , 6 0 7 P S , 5 0 7 P S t , h t d i W e s l u P I D W P W 1 V LI V , V 4 . 0 = HI V X 8 . 0 = C C , d l o h s e r h T t u p n I I D W W O L H G I H 5 . 3 8 . 0 V L 3 1 8 P S , 6 0 7 P S , 5 0 7 P S V C C V 5 = t n e r r u C t u p n I I D W 5 7 - 0 3 0 2 - 5 7 µA L 3 1 8 P S , 6 0 7 P S , 5 0 7 P S V = I D W C C L 3 1 8 P S , 6 0 7 P S , 5 0 7 P S V 0 = I D W ABSOLUTE MAXIMUM RATINGS This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability and cause permanent damage to the device. Input Current: Continuous Power Dissipation Plastic DIP (derate 9.09mW/°C above +70°C)727mW Mini SO (derate 4.10mW/°C above +70°C) 330mW SPECIFICATIONS µs V C

Note 1: T h e i n p u t v o l t a g e l i m i t s o n P F I a n d M R c a n b e e x c e e d e d i f t h e i n p u t c u r r e n t i s l e s s t h a n 1 0 m A . Note 2: Applies to both RESET in the SP705-SP708 and RESET in the SP707/708/813L/813M. Figure 1. Pinouts

Table 1. Device Pin Description

June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation

FEATURES

The SP705-708/813L series provides four key functions: 1. A reset output during power-up, power-down and brownout conditions. 2. An independent watchdog output that goes LOW if the watchdog input has not been toggled within 1.6 seconds. 3. A 1.25V threshold detector for power-fail warning, low battery detection, or monitoring a power supply other than +5V. 4. An active-LOW manual-reset that allows RESET to be triggered by a pushbutton switch. The SP707/708 devices are the same as the SP705/706 devices except for the active-HIGH RESET substitution of the watchdog timer. The SP813L is the same as the SP705 except an active-HIGH RESET is provided rather than an active-LOW RESET. The SP705/707/813L devices generate a reset when the supply voltage drops below 4.65V. The SP706/708 devices generate a reset below 4.40V. The SP705-708/813L series is ideally suited for applications in automotive systems, intelligent instruments, and battery-powered computers and controllers. The SP705-708/813L series is ideally applied in environments where monitoring of power supply to a µP and its related components is critical. THEORY OF OPERATION The SP705-708/813L series is a microprocessor (µP) supervisory circuit that monitors the power supplied to digital circuits such as microprocessors, microcontrollers, or memory. The series is an ideal solution for portable, battery-powered equipment that requires power supply monitoring. Implementing this series will reduce the number of components and overall complexity. The watchdog functions of this product family will continuously oversee the operational status of a system. The operational features and benefits of the SP705-708/813L series are described in more detail below. RESET Output A microprocessor's reset input starts the µP in a known state. The SP705-708/813L series asserts reset during power-up and prevents code execution errors during power- down or brownout conditions. On power-up, once V CC reaches 1.1V, RESET is a guaranteed logic LOW of 0.4V or less. As VCC rises, RESET stays LOW. When VCC rises above the reset threshold, an internal timer re- leases RESET after 200ms. RESET pulses LOW whenever V CC dips below the reset thresh- old, such as in a brownout condition. When a brownout condition occurs in the middle of a previously initiated reset pulse, the pulse con- tinues for at least another 140ms. On power- down, once V CC falls below the reset threshold, RESET stays LOW and is guaranteed to be 0.4V or less until V CC drops below 1.1V. The SP707/708/813L active-HIGH RESET output is simply the complement of the RESET output and is guaranteed to be valid with V CC down to 1.1V. Some µPs, such as Intel's 80C51, require an active-HIGH reset pulse. Watchdog Timer The SP705/706/813L watchdog circuit monitors the µP's activity. If the µP does not toggle the watchdog input (WDI) within 1.6 seconds and WDI is not tri-stated, WDO goes LOW. As long as RESET is asserted or the WDI input is tri-stated, the watchdog timer will stay cleared and will not count. As soon as RESET is released and WDI is driven HIGH or LOW, the timer will start counting. Pulses as short as 50ns can be detected.

noninverting input are not internally connected. prepare for an orderly power-down.

708 RESET output no longer sinks current, it

Figure 17. Monitoring Both +5V and +12V Power Figure 16. Typical Operating Circuit

falls below approximately 11V. Figure 18. Monitoring a Negative Voltage Supply Figure 19. Interfacing to Microprocessors with the RESET output to other system components.

June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation

Applications

The SP705-708/813L series offers unmatched performance and the lowest power consumption for these industry standard devices. Refer to Figures 20 and 21 for supply current performance characteristics rated against temperature and supply voltages. Table 2shows how the SP705-708/813L series can be used instead of the Dallas Semiconductor DS1232LP/LPS. Table 2 illustrates to a designer the advantages and trade- offs of the SP705-708/813L series compared to the Dallas Semiconductor device. While the names of the pin descriptions may differ, the functions are the same or very similar. Figure 20. Supply Current vs. Temperature Figure 21. Supply Current vs. Supply Voltage

Table 2. Device Overview on Dallas Semiconductor

June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation

June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation

June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation

June 2008 Rev C SP705 Low Power Microprocessor Supervisory Circuits © 2008 Exar Corporation

ORDERING INFORMATION

Please consult the factory for pricing and availability on a Tape-On-Reel option. All parts available lead free and in tape & reel: Example SP708CU-L/TR For further assistance: Email: customersupport@exar.com EXAR Technical Documentation: http://www.exar.com/TechDoc/default.aspx? Exar Corporation Headquarters and Sales Office

48720 Kato Road

Fremont, CA 94538 main: 510-668-7000 fax: 510-668-7030 EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration purposes and may vary depending upon a user’s specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receives, in writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes all such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances.