MIC841_05 Datasheet, PDF (1/8 Pages) Micrel Semiconductor – Comparator with Reference

MIC841/2
MIC841/842
Comparator with Reference
Micrel
General Description
The MIC841 and MIC842 are micropower, precision voltage
comparators with an on-chip voltage reference.
Both devices are intended for voltage monitoring applications.
External resistors are used to set the voltage monitor threshold.
When the threshold is crossed, the outputs switch polarity.
The MIC842 incorporates a voltage reference and comparator
with fixed internal hysteresis; two external resistors are used to
set the switching threshold voltage. The MIC841 provides a
similar function with user adjustable hysteresis; this part re-
quires three external resistors to set the upper and lower
thresholds (the difference between the threshold voltages
being the hysteresis voltage).
Both the MIC841 and MIC842 are available with push-pull or
open-drain output stage. The push-pull output stage is config-
ured either active high or active low; the open-drain output stage
is only configured active high.
Supply current is extremely low (1.5µA, typical), making it ideal
for portable applications.
The MIC841/2 is supplied in Micrel’s Teeny™ 5-lead SC-70
package.
Data sheets and support documentation can be found on
Micrel’s web site at www.micrel.com.
Teeny™
Features
• Optimized for PDAs, cellular telephones, pagers,
and other battery-powered devices
• Output can be pulled up to 6V regardless of supply
voltage (841NBC5 only)
• High ±1.25% voltage threshold accuracy
• Built in hysteresis for noise suppression
(MIC842)
• Extremely low 1.5µA typical supply current
• Immune to brief input transients
• Teeny™ 5-lead SC-70 package
Applications
• PDAs
• Pagers
• Cordless phones
• Consumer electronics
• Embedded controllers
• Personal electronics
Typical Application
V_IN V_DD
MIC841
R1
5
VDD
OUT ⁴
3
LTH
R2
1 _{HTH GND} 2
V_OUT
V_LTH > V_HTH
V_REF = 1.24V
1.5V ≤ V_DD ≤ 5.5V
R3
V_IN V_DD
MIC842
VDD OUT
5
4
R1
INP GND
1
2
R2
V_OUT
V_REF = 1.24V
1.5V ≤ V_DD ≤ 5.5V
Threshold Detection with Hysteresis Set by a Third
External Resistor
Threshold Detector with Internal Fixed Hysteresis
Teeny™ is a trademark of Micrel, Inc.
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com
January 2005
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MIC841/2