IMP183 4/A/D POWER MANAGEMENT Dual 5V and 3.3V µP Power Supply Supervisors w/Manual Reset – Push-Pull and Open-Dr ain Outputs – Select able T r ip Point Toler ance The IMP1834 supervisors simultaneously monitor both 3.3V and 5V power sources and issue reset signals when either supply is out of tolerance. When an out-of-tolerance condition is detected, the output-reset signal of the affected supply becomes active and resets the system microprocessor/microcontroller. On power-up and after the supply voltage returns to an in-tolerance condition, the reset signal remains active for approximately 350ms. This allows the power supply and system microprocessor to stabilize. The IMP1834 supervisors are pin-compatible with devices from Dallas Semiconductor and require up to 40% less current. Tolerance levels are independently selectable for both supplies. Tolerance options are 5- and 10-percent for the 5V supply and for the 3.3V supply, 10- and 20-percent. The IMP1834 and IMP1834D have push-pull reset output stages. The IMP1834A active LOW reset outputs are open drain devices that can both be connected to either 5 volt or 3.3 volt supply. The IMP1834 and IMP1834A have active LOW reset outputs. The IMP1834D has active HIGH reset outputs. All devices can issue reset signals through an internally debounced pushbutton reset input that affects both reset outputs. All devices operate over the extended industrial temperature range. Devices are available in 8-pin DIP, surface mount 8-pin SO and 8-pin MicroSO packages. Die are also available. Key Features ◆ Lower power, pin-compatible replacements for the Dallas DS1834 — 40% lower maximum supply current: 30µA vs 50µA ◆ Monitor 5V and 3.3V supplies simultaneously ◆ 5V and 3.3V power-on reset ◆ 350ms reset time ◆ Debounced pushbutton reset input ◆ Push-Pull CMOS output — IMP1834, IMP1834D — Eliminates external pull-up resistors — Active LOW (IMP1834), HIGH (IMP1834D) ◆ Open drain output — IMP1834A — Active LOW ◆ Selectable 5V and 3.3V trip point tolerance ◆ Internal power drawn from highest input voltage, 5V or 3.3V ◆ Precision temperature-compensated voltage reference and comparator ◆ Low-cost surface mount SO, compact MicroSO and DIP packages ◆ Wide operating temperature, – 40°C to +85°C IMP1834A 2 5VRESET Block Diagram 7 IMP1834 5VIN 3.3VRESET 1 1834_02.eps 5VTOL 3 5V Tolerance Bias + Low TC Reference – 40kΩ PBRST 5 3.3VIN 8 3.3VTOL GND 6 4 3.3V Tolerance Bias For IMP1834D 350 ms Delay 2 350 ms Delay 7 5VRESET 5VRESET (IMP1834D) Pushbutton Level Sense and Debounce For IMP1834D + 3.3VRESET 3.3VRESET (IMP1834D) – 1834_01.eps © 1999 IMP, Inc. 408-432-9100/www.impweb.com 1 IMP183 4/A/D Pin Configuration DIP/SO/MicroSO 5VIN 1 5VRESET* 2 5VTOL 3 GND 4 IMP1834 IMP1834A IMP1834D 8 3.3VIN 7 3.3VRESET* 6 3.3VTOL 5 PBRST * IMP1834D reset outputs are active HIGH (5VRESET and 3.3VRESET). Outputs are open drain for IMP1834A. 1834_03.eps Pin Descriptions Pin Number Name 1 5VIN 2 5VRESET 5VRESET 3 5VTOL 4 GND 5 PBRST 6 3.3VTOL 7 3.3VRESET 3.3VRESET 8 3.3VIN Function 5V power supply input. 5V reset output (Active LOW, IMP1834, IMP1834A. Open drain outputs for IMP1834A). 5V reset output (Active HIGH, IMP1834D). 5V input tolerance select: 10% tolerance for 5VTOL 5VIN and 5% tolerance for 5VTOL = GND. Ground. Debounced manual pushbutton reset input (40kΩ internal pull up). 3.3V input tolerance select: 20% tolerance for 3.3VTOL = 3.3VIN, and 10% tolerance for 3.3VTOL = GND. 3.3V reset output (Active LOW, IMP1834, IMP1834A. Open drain outputs for IMP1834A). 3.3V reset output (Active HIGH, IMP1834D). 3.3V power supply input. 1834_01t.eps Ordering Information Part Number Package Operating Temperature Range Reset Polarity Output Stage IMP1834 8-DIP – 40°C to 85°C LOW Push-Pull IMP1834EMA MicroSO – 40°C to 85°C LOW Push-Pull IMP1834S 8-SO – 40°C to 85°C LOW Push-Pull IMP1834/D DICE 25°C LOW Push-Pull IMP1834A 8-DIP – 40°C to 85°C LOW Open Drain IMP1834AEMA MicroSO – 40°C to 85°C LOW Open Drain IMP1834AS 8-SO – 40°C to 85°C LOW Open Drain IMP1834A/D DICE 25°C LOW Open Drain IMP1834D 8-DIP – 40°C to 85°C HIGH Push-Pull IMP1834DEMA MicroSO – 40°C to 85°C HIGH Push-Pull IMP1834DS 8-SO – 40°C to 85°C HIGH Push-Pull IMP1834D/D DICE 25°C HIGH Push-Pull 1834_02t.eps 2 408-432-9100/www.impweb.com © 1999 IMP, Inc. IMP183 4/A/D Absolute Maximum Ratings Voltage on VIN pins . . . . . . . . . . . . . . . . –0.5V to 7V Voltage on 5VRESET . . . . . . . . . . . . . . . –0.5V to (+5VIN +0.5V) (IMP1834, IMP1834D) Voltage on 3.3VRESET . . . . . . . . . . . . . . –0.5V to (+3.3VIN +0.5V) (IMP1834, IMP1834D) Voltage on PBRST and reset outputs . . –0.5V to the greater of 5VIN +0.5V or 3.3VIN +0.5V (IMP1834A) Operating Temperature Range . . . . . . . –40°C to 85°C Storage Temperature . . . . . . . . . . . . . . . –55°C to 125°C Soldering Temperature . . . . . . . . . . . . . . 260°C for 10 seconds Voltages measured with respect to ground. These are stress ratings only and functional operation is not implied. Electrical Characteristics Recommended DC operating condition over the operating temperature range of –40°C to +85°C. All voltages are referenced to ground. Parameter 5V Supply Voltage (5VIN) 3.3V Supply Voltage (3.3V) PBRST Input High Level PBRST Input High Level PBRST Input Low Level Symbol 5VIN 3.3VIN VIH VIH VIL Conditions Both 3.3VIN and 5VIN ≥ 2.7V Both 3.3VIN and 5VIN ≤ 2.7V Min Typ 1.2 1.2 2 VINMAX – 0.4V – 0.3 Max Units 5.5 5.5 VINMAX + 0.3V V V V V V 0.5 Unless otherwise noted, VIN = 1.2V to 5.5V and specifications are over the operating temperature range of –40°C to +85°C. Parameter Symbol Output Voltage Input Leakage Output Current VOH IIL IOH Output Current IOL 5V Operating Current ICC 3.3V Operating Current ICC 5V Trip Point 5V Trip Point 3.3V Trip Point 3.3V Trip Point Output Capacitance PBRST Manual Reset Minimum Low Time PBRST Stable LOW to Reset Active Reset Active Time VCC Detect Noise Immunity VCC Slew Rate VCC Slew Rate VCC Detect to RESET or RESET © 1999 IMP, Inc. VINTP VINTP VINTP VINTP COUT tPB Conditions Min Typ –1.0 Output = 2.4V. Either 3.3VIN or 5VIN ≥ 2.7V. (IMP1834/1834D only) Output = 0.4V. Either 3.3VIN or 5VIN ≥ 2.7V. (IMP1834/1834D only) 3.3VIN and 5VIN ≤ 5.5V, RESET outputs open. 3.3VIN and 5VIN ≤ 3.6V, RESET outputs open. 5VTOL = GND 5VTOL = 5VIN 3.3VTOL = GND 3.3VTOL = 3.3VIN Units +1.0 V µA µA 350 +10 4.50 4.25 2.80 2.47 mA 16 30 µA 12 25 µA 4.63 4.38 2.88 2.55 4.75 4.49 2.97 2.64 10 V V V V pF ms 2 ms ms µs µs ns ms 2 tPDLY tRST tRPD tF tR tRPU Max VIN – 0.1V VINTP (MAX) to VINTP (MIN) VINTP (MIN) to VINTP (MAX) trise = 5µs 408-432-9100/www.impweb.com 200 350 500 2 300 0 200 350 500 3 IMP183 4/A/D Application Information Operation – Power Monitor Reset Signal Polarity and Output Stage Structure The IMP1834 supervisors simultaneously detect out-of-tolerance power supply conditions on both 3.3V and 5V power supplies. If the voltages at 5VIN or 3.3VIN are outside the tolerance band, the reset for the failing supply voltage becomes active. When the monitored supply returns to an in-tolerance state, the reset remains active for approximately 350ms before returning to the inactive state. The IMP1834 and IMP1834A supervisors have active LOW reset signals. The IMP1834D reset outputs are active HIGH. On power-up, the reset signals are kept active for approximately 350ms after the power supply voltages have reached the selected tolerance. This allows the power supply and microprocessor to stabilize before the reset is removed. All supply current for the IMP1834 devices is drawn from the input (5VIN or 3.3VIN) with the highest voltage level. The outputs draw current from their input supplies 5VIN and 3.3VIN. tR VINTP (Max) IMP Part IMP1834 IMP1834EMA IMP1834S IMP1834A IMP1834AEMA IMP1834AS IMP1834D IMP1834DEMA IMP1834DS RESET Polarity Output Stage Configuration LOW LOW LOW LOW LOW LOW HIGH HIGH HIGH Push-Pull Push-Pull Push-Pull Open Drain Open Drain Open Drain Push-Pull Push-Pull Push-Pull Trip Point Tolerance Selection VINTP VINTP (Min) The IMP1834 and IMP1834D have CMOS push-pull output stages. The IMP1834A has open drain reset outputs. The 3.3VTOL and 5VTOL inputs allow independent selection of the reset trip points. If 5VTOL is connected to the 5V supply input, a 10% tolerance is selected. If 5VTOL is grounded, a 5% tolerance is selected. VIN tRPU RESET VOH VOL RESET (IMP1834D Only) If 3.3VTOL is connected to the 3.3V supply input, a 20% tolerance is selected. If 3.3VTOL is grounded, a 10% tolerance is selected. See Table 1. The 3.3VTOL and 5VTOL tolerance select inputs should be tied to ground or to the respective input supply voltage pin, 3.3VIN or 5VIN. 1834_10.eps Figure 1. Timing Diagram: Power Up VIN tF VINTP (Max) VINTP VINTP (Min) > tRPD RESET VOH RESET Slews with VCC VOL RESET (IMP1834D Only) 1834_09.eps Figure 2. Timing Diagram: Power Down 4 408-432-9100/www.impweb.com © 1999 IMP, Inc. IMP183 4/A/D Application Information Table 1. Threshold Selection 3.3V Input Tolerance Select 5V Input TRIP Point (V) 3.3V Tolerance MIN Nominal — — — 5VTOL = 5VIN 5VTOL = GND TRIP Point (V) MAX 5V Tolerance MIN Nominal MAX — 10% 4.25 4.38 4.49 — — — — 5% 4.5 4.63 4.75 3.3VTOL = 3.3VIN 20% 2.47 2.55 2.64 — — — — 3.3VTOL = GND 10% 2.80 2.88 2.97 — — — — 1834_03t.eps Manual Reset Operation Pushbutton switch input, PBRST, allows the user to override the internal trip point detection circuits and issue reset signals. The pushbutton input is debounced and is pulled HIGH through a 40kΩ, internal pull-up resistor. 5V 3.3V IMP1834 1 2 3 4 5VIN 3.3VIN 5VRESET 3.3VRESET 5VTOL GND tPB PBRST 3.3VTOL PBRST tPDLY 8 6 tRST RESET 5 Figure 3. Pushbutton Reset VIH VIL 7 1834_04.eps © 1999 IMP, Inc. When at least one of the reset outputs is not asserted, a pushbutton initiated reset signal can be issued by holding PBRST LOW for at least 2ms. When PBRST is held LOW, both resets become active and remain active for approximately 350ms after PBRST returns HIGH. See Figure 3 and Figure 4. VOH RESET (IMP1834D) VOL 1834_05.eps Figure 4. Timing Diagram: Pushbutton Reset 408-432-9100/www.impweb.com 5 IMP183 4/A/D Application Information Reset Output Signal Reset output signals are valid as long as either voltage at 5VIN or 3.3VIN is above 1.2V. In addition, the IMP1834 has push-pull outputs that can remain valid below a 1.2V input level. To sink current below 1.2V, a resistor should be connected from the reset output to ground. This resistor guarantees a valid reset signal down to 0V. A 100kΩ value is suggested. IMP1834A 10kΩ 1 2 The IMP1834A open drain reset outputs require pull-up resistors and must be low enough in value to pull the output into a HIGH state. Resistor value is not critical in most applications and a value of 10kΩ is suggested. See Figure 5 and Figure 6. The IMP1834A open drain reset outputs can be connected to the same potential through a single pull up resistor. In this configuration a failure on either supply will generate an active LOW reset. If the outputs are pulled-up to different voltages, the reset outputs (pin 2 and pin 7) should not be connected. See Figure 7. 3.3V 5V 3 4 5VIN 3.3VIN 5VRESET 3.3VRESET 5VTOL 3.3VTOL GND PBRST 10kΩ 7 6 5 1834_07.eps Figure 6. IMP1834A Open Drain Output Pull-Up Resistor 5V 3.3V 5V or 3.3V IMP1834A µP Input RESET 8 1 100kΩ 2 1834_06.eps 3 4 Figure 5. IMP1834 RESET Valid to 0V 5VIN 3.3VIN 5VRESET 3.3VRESET 5VTOL GND 3.3VTOL PBRST 8 10kΩ 7 6 5 1834_08.eps Figure 7. IMP1834A Wired “OR” Connection 6 408-432-9100/www.impweb.com © 1999 IMP, Inc. IMP183 4/A/D Package Dimensions Absolute Maximum Ratings MicroSO (8-Pin) Inches Millimeters Min a Max Min Max MicroSO (8-Pin)* + E1 E L D C A2 D A e b 0.10mm 0.004in MicroSO (8-Pin).eps A A1 A2 b C D e E E1 L a ––––– 0.0433 0.0020 0.0059 0.0295 0.0374 0.0098 0.0157 0.0051 0.0091 0.1142 0.1220 0.0256 BSC 0.193 BSC 0.1142 0.1220 0.0157 0.0276 0° 6° A A1 B C e E H L D 0.053 0.004 0.013 0.007 A1 –––– 1.10 0.050 0.15 0.75 0.95 0.25 0.40 0.13 0.23 2.90 3.10 0.65 BSC 4.90 BSC 2.90 3.10 0.40 0.70 0° 6° SO (8-Pin)** SO (8-Pin) 0°– 8° L H E 0.069 0.010 0.020 0.010 1.35 0.10 0.33 0.19 0.157 0.244 0.050 0.197 3.80 5.80 0.40 4.80 0.050 0.150 0.228 0.016 0.189 1.75 0.25 0.51 0.25 1.27 4.00 6.20 1.27 2.00 Plastic DIP (8-Pin)*** C D A e B A1 SO (8-Pin).eps Plastic DIP (8-Pin) D1 E D E1 A A2 L A1 A ––––– 0.210 A1 0.015 ––––– A2 0.115 0.195 b 0.014 0.022 b2 0.045 0.070 b3 0.030 0.045 D 0.355 0.400 D1 0.005 ––––– E 0.300 0.325 E1 0.240 0.280 e 0.100 ––––– eA 0.300 ––––– eB ––––– 0.430 eC ––––– 0.060 L 0.115 0.150 *** JEDEC Drawing MO-187AA *** JEDEC Drawing MS-112AA *** JEDEC Drawing MS-001BA –––– 0.38 2.92 0.36 1.14 0.80 9.02 0.13 7.62 6.10 5.33 ––––– 4.95 0.56 1.78 1.14 10.16 ––––– 8.26 7.11 2.54 7.62 ––––– 10.92 2.92 3.81 1834_t04.at3 0°–15° e C b2 b eA eB Plastic DIP (8-Pin)a.eps © 1999 IMP, Inc. 408-432-9100/www.impweb.com 7 IMP183 4/A/D IMP, Inc. Corporate Headquarters 2830 N. First Street San Jose, CA 95134-2071 Tel: 408-432-9100 Tel: 800-438-3722 Fax: 408-434-0335 Fax-on-Demand: 1-800-249-1614 (USA) Fax-on-Demand: 1-303-575-6156 (International) e-mail: [email protected] http://www.impweb.com The IMP logo is a registered trademark of IMP, Inc. All other company and product names are trademarks of their respective owners. © 1999 IMP, Inc. Printed in USA Publication #: 1009 Revision: A Issue Date: 07/02/99 Type: Preliminary