View MIC8114_32041.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

MIC8114 Microprocessor Reset Circuit
MIC8114
Microprocessor Reset Circuit
Description
The MIC8114 is an inexpensive microprocessor reset circuit that monitor power supplies in microprocessor based systems. The function of this device is to assert a reset if either the power supply drops below a designated reset threshold level or MR is forced low. The MIC8114 has an active low RESET output. The reset output is guaranteed to remain asserted for a minimum of 790ms after VCC has risen above the designated reset threshold level. The MIC8114 comes in a 4-pin SOT-143 package.
Pin Configuration
Top View
GND 1
4 VCC
MIC81 14
RESET 2 3 MR
Features Typical Applications
* Portable Equipment * Intelligent Instruments * Critical Microprocessor Power Monitoring * Printers/Computers * Controllers
* RESET Remains Valid with VCC as Low as 1.4V * Precision Voltage Monitor for 3.3V Power Supplies * Available in 4-Pin SOT-143 Package * <15A Supply Current * 790ms Minimum Reset Pulse Width * Manual Reset Input * Specifically tailored to the reset
requirements of the AMD Elan SC400/410
Typical Operating Circuit Ordering Information
Part MIC8114TU Package 4-Lead SOT-143 Temp. Range -40C to +85C
VCC VCC
MIC81 14
VCC
P
Place the device suffix of desired reset threshold voltage from table above in blank to complete the part number.
MR
RESET
RESET
1
MIC8114 Microprocessor Reset Circuit
Absolute Maximum Ratings
Terminal Voltage VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 6.0V MR . . . . . . . . . . . . . . . . . . . . . -0.3V to (VCC + 0.3V) Input Current, VCC, MR . . . . . . . . . . . . . . . . . . . . 20mA Output Current, RESET . . . . . . . . . . . . . . 20mA Rate of Rise, VCC . . . . . . . . . . . . . . . . . . . . . . 100V/s Operating Temperature Range MIC8114TU . . . . . . . . . . . . . . . . . . . . . . . . -40C to 85C Storage Temperature Range . . . . . . . . . . . . .-65C to 150C Lead Temperature (Soldering - 10 sec.) . . . . . . . . . . . 300C Power Dissipation (TA = +70C) . . . . . . . . . . . . . . . . 320mW
Stresses above those listed under ABSOLUTE MAXIMUM RATINGS may cause permanent device failure. Functionality at or above these limits is not implied. Exposure to absolute maximum ratings for extended periods may affect device reliability. Operating ranges define those limits between which the functionality of the device is guaranteed.
Electrical Characteristics
VCC = 3.3V for MIC8114T, TA = Operating Temperature Range, unless otherwise noted. Parameter Operating Voltage Range, VCC Supply Current, ICC Reset Voltage Threshold, VTH Reset Timeout Period RESET Output Voltage, VOH RESET Output Voltage, VOL ISource = 500A VCC=VTH Min., ISink =1.2mA VCC>1.4V, ISink =50A, TA = 0C to 70C VCC>1.6V, ISink =50A, TA = -40C to 85C 10 0.5 0.7 X VCC 0.25 X VCC 10 20 100 30 3.00 790 0.8 X VCC 0.3 0.3 0.3 Conditions TA = 0C to 70C TA = -40C to 85C Min 1.4 1.6 9 3.08 1200 Typ Max 5.5 5.5 15 3.15 1800 Units V A V ms V V V V s s V V k ns
MR Minimum Pulse Width MR to Reset Delay MR Input Threshold, VIH MR Input Threshold, VIL MR Pull-Up Resistance MR Glitch Immunity
2
MIC8114 Microprocessor Reset Circuit
Pin Functions
Pin Name GND RESET
Pin No. 1 2
Description IC Ground Pin. RESET goes low if either VCC falls below the supply reset threshold or if MR is asserted. RESET remains asserted for one reset timeout period (790ms min.) after both VCC exceeds the supply reset threshold and MR is deasserted. Manual reset input. A logic low on MR forces a reset. The reset will remain asserted as long as MR is held low and for one reset timeout period (790ms) min.) after MR goes high. This input can be shorted to ground via a switch or driven from CMOS or TTl logic. Pulled high internally through a 20k resistor. Float if unused.
MR
3
VCC
4
Power supply input.
3
MIC8114 Microprocessor Reset Circuit
Block Diagram
VCC
MR (3)
RESET GENERATOR
RESET (2)
VCC (4) Reset Threshold (V)
+ -
GND (1)
Figure 1. MIC8114 Block Diagram
4
MIC8114 Microprocessor Reset Circuit
Circuit Description
Microprocessor Reset The RESET pin is asserted whenever VCC falls below the reset threshold voltage or if MR (manual reset) is forced low. The reset pin remains asserted for a period of at least 790ms after VCC has risen above the reset threshold voltage or MR has returned high. The reset function ensures the microprocessor is properly reset and powers up into a known condition after a power failure. RESET will remain valid with VCC as low as 1.4V. VCC Transients The MIC8114 is relatively immune to negative-going VCC glitches below the reset threshold. Typically, a negative-going transient 125mV below the reset threshold with a duration of 25s or less will not cause an unwanted reset.
VCC
Vthr
MR t1 RESET t1
Figure 2. Reset Timing Diagram
VCC VCC VCC P RESET
100K
MIC81 14
RESET
RESET Valid to 0V A resistor can be added from the RESET pin to ground to ensure the RESET output remains low with V CC down to 0V. A 100K resistor connected from RESET to ground is recommended. The size of the resistor should be large enough to not load the RESET output and small enough to pull-down any stray leakage currents.
Figure 3. RESET Valid to VCC = 0V.
5
MIC8114 Microprocessor Reset Circuit
6
MIC8114 Microprocessor Reset Circuit
Packaging Information
U Package, 4-Pin SOT-143 Small-Outline Transistor Package
0.079 0.071
0.055 0.047
0.098 0.083
0.037 0.030
0.021 0.015
0.120 0.105 0.0059 0.0035 0-81/4
0.040 0.031
0.080 0.070
0.004 0.001
0.010 0.005
Dimensions are in inches.
Device Marking Information
Lot Code
NVXX = MIC8114
7
MIC8114 Microprocessor Reset Circuit
Packaging Information
Tape and Reel Information
4.0-0.1 2.0-0.05
fl1.5-0.1
1.75-0.1
3.5-0.05 8.0-0.3
4.0-0.1
fl1.1-0.1
2.7-0.1
1.2-0.1
3.1-0.1
Dimensions are in millimeters.
8

▲Up To Search▲

Price & Availability of MIC8114

	To Download MIC8114 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .