TECHNICAL DATA POWER SUPPLY CONTROL WITH BUILT-IN WATCHDOG TIMER IN1232 IN1232 is designed to monitor power supply within the system of reset signal generation for microprocessors. It is used in monitor systems for controlling various processes and entities. Packaged in 8-pin SOP or DIP. Features: • • • • Rated supply voltage 5.0 V Accurate 5% or 10% microprocessor power supply monitoring Programming of watchdog timer overflow time Generation of reset signals at power on for correct microproces sor start. ORDERING INFORMATION IL1232N Plastic IL1232D SOIC TA = -40° to 85° C for all packages. The chip contains reference voltage source, analog comparator, Watchdog timer, circuit for monitoring power supply deviation accuracy. . PBRST 01 Functions: • • • Reset signal generation after power failure/ error Reset signal generation from external “RESET” pushbutton Reset signal generation from watchdog timer 08 Vcc TD 02 07 ST TOL 03 06 RST GND 04 05 RST Fig 1 – PIN ASSIGNMENT Table 1 – Absolute maximum Symbol ratings Parameter Typical Units Min Max - 7.0 V V V VСС Supply voltage VIH VIL ТA Input voltage, high level Input voltage, low level Operating temperature range -1.0 -40 7.0 +85 °С Tstg Storage temperature -60 +125 °С * Stresses beyond 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 beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. 2011, February, Rev. 01 I N1232 Table 2 – Recommended operating conditions Symbol Typical Parameter Min Max Units VСС Supply voltage 4.5 5.5 V VIH VIL ТA Input voltage, high level Input voltage, low level Operating temperature range 2.0 -0.3 -20 UСС+0.3 0.8 +70 V V °С Table 3 DC electrical characteristics (TAmb = -40° to +85°С) Symbol Parameter ILIL1 Input leakage current, low level, ST, TOL VCC=5 V±10%, Input leakage current, low level, TD VCC=5 V±10%, Input leakage current, low level, PBRST VCC=5 V±10%, Input leakage current, high level, ST, TOL VCC =5 V±10%, Input leakage current, high level, TD VCC =5 V±10%, Output current, high level, RST VCC =5 V±10%, Output current, low level, RST, RST VCC =5 V±10%, Output voltage, high level, RST ILIL2 ILIL3 ILIH1 ILIH2 IOH IOL VOH Test conditions Typical Units min max - -1 µА - -300 µА - -1000 µА - 1 µА - 300 µА -8 - µА 8 - mА VCC =5 V±10%, VСС-0.5 - V VIL=0 V VIL=0 V VIL=0 V VIH=VCC VIH=VCC VOH=2.4 V VOL=0.4 V IOH= -500 µА VOH1 Output voltage, high level,- RST VCC =2 V, VСС-0.5 - V VOL Output voltage, low level, RST Operating current VCC =2 V, - 0.4 V VCC =5 V±10% - 2 mА VCC TP1 VCC trip point VCC TP2 VCC trip point TOL = GND TOL = VCC 4.5 4.25 4.74 4.49 V V IСС IOH= -500 µА IOL=1 mА 2011, February, Rev. 01 I N1232 Table 4 – AC electrical characteristics (Тamb = from -40 to +85 °С) Symbol tTD1 Parameter Watchdog timer overflow time tTD2 tTD3 tPDLY PBRST stable low to RST and RST tRST Reset active time tRPD VCC fail detect to RST and tRPU VCC detect to RST and RST RST transition Typical Test conditions min max VCC =5.0 V±10% 62.5 250 tST≥20 ns TD = GND TD disconnected TD = VCC ms 250 500 1000 2000 VCC =5.0 V±10% - 20 ms ms ms 250 1000 ms - 175 µs 250 1000 ms tPB≥20 ms VCC =5.0 V±10% tPB≥20 ms VCC =from 5.0 to 4.0 V tF≥10 µs VCC = from 5.0 to 4.0 V tR≥1 µs Units Table 5 – Pin description Pin Symbol Description 01 PBRST 02 TD 03 TOL Selects 5% or 10% VCC Detect 04 GND Ground 05 RST Reset output (Active High) 06 RST Reset output (Active Low, open drain) 07 ST Strobe Input 08 VCC Supply output from voltage source Pushbutton reset input Time Delay Set 2011, February, Rev. 01 I N1232 tPB ______ PBRST tPDLY VIH VIL tRST ____ RST RST tPB≥20 ms tPDLY≤20 ms 250 ms≤tRST≤1000 ms Fig. 2 – Timing diagram of forming reset signal from external PBRST control button ___ ST Invalid strob t Indeterminate strob Valid strob MAX MIN ST t TD1 -t TD3 RST tST ≥20 нс 62.5 ms≤ tTD1 ≤250 ms 250 ms≤ tTD2 ≤1000 ms 500 ms≤ tTD3 ≤2000 ms Fig. 3 – Timing diagram : Strobe input 2011, February, Rev. 01 I N1232 tF VCC 4.75 V 4.5 V 4.25 V ____ RST tRPD VOH RST μs tF ≥10 V tRPD ≤175 μs OL Fig. 4 – Timing diagram: power error / down to VCCTP tR 4.75 V VCCTP 4.25 V tRPU VCC RST RST VOH tR ≥1 μs 250 ms≤ tRPU ≤1000 ms VOL Fig. 5 – Timing diagram: Power-Up/ Stable 2011, February, Rev. 01 I N1232 ST Watchdog timer TD VCC Vcc tolerance Bias TOL Referance voltage source + - RST RST PBRST GND Fig.6 Block diagram IN1232 Fig.7 Application Circuit : Watchdog Timer 2011, February, Rev. 01 I N1232 N SUFFIX PLASTIC DIP (MS – 001BA) A Dimension, mm 5 8 B 1 4 MIN MAX A 8.51 10.16 B 6.1 7.11 C L F Symbol C 5.33 D 0.36 0.56 F 1.14 1.78 -T- SEATING PLANE N G M K 0.25 (0.010) M J H D T NOTES: 1. Dimensions “A”, “B” do not include mold flash or protrusions. Maximum mold flash or protrusions 0.25 mm (0.010) per side. G 2.54 H 7.62 J 0° 10° K 2.92 3.81 L 7.62 8.26 M 0.2 0.36 N 0.38 D SUFFIX SOIC (MS - 012AA) Dimension, mm A 8 5 B H 1 G P 4 D K MIN MAX A 4.8 5 B 3.8 4 C 1.35 1.75 D 0.33 0.51 F 0.4 1.27 R x 45 C -T- Symbol SEATING PLANE J F 0.25 (0.010) M T C M NOTES: 1. Dimensions A and B do not include mold flash or protrusion. 2. Maximum mold flash or protrusion 0.15 mm (0.006) per side for A; for B ‑ 0.25 mm (0.010) per side. M G 1.27 H 5.72 J 0° 8° K 0.1 0.25 M 0.19 0.25 P 5.8 6.2 R 0.25 0.5 2011, February, Rev. 01