Micrel MIC845HBC5 Micro-power comparator/ battery monitor Datasheet

MIC845
Micro-Power Comparator /
Battery Monitor
General Description
The MIC845 is a precision micro-power voltage
comparator with an on-chip 2.55V reference voltage
source.
Intended for voltage monitoring applications, the
MIC845 can be used with an external resistor divider
to detect a wide range of voltages, or without
external resistors to directly monitor voltages with its
high input impedance CMOS input.
The MIC845 incorporates a voltage reference and
comparator with fixed internal hysteresis. When the
2.55V internal threshold is crossed, the output
switches polarity.
MIC845 is available with a push-pull or open-drain
output stage. The push-pull output stage is
configured for both active high or active low output;
the open-drain output stage is only configured active
high.
Supply current is extremely low (typically 1µA),
making it ideal for portable applications.
MIC845 is supplied in Micrel’s Teeny™ 5-lead SC70 package.
Data sheets and support documentation can be
found on Micrel’s web site at www.micrel.com.
Teeny™
Features
•
•
•
•
Extremely low 1µA supply current (typical)
2.55V on chip reference
±2% voltage threshold accuracy
Optimized for PDAs, cellular telephones, pagers,
and other battery-powered devices
• Open-drain output can be pulled up to 6V
regardless of supply voltage
• 5-lead SC-70 package
Applications
•
•
•
•
•
•
PDAs
Pagers
Cordless phones
Portable electronics
Motherboards
Bladed servers
____________________________________________________________________________________________________
Typical Applications
VIN
3.3V
VDD
MIC845
MIC845
VDD
OUT
Memory
power
R1
INP
GND
R2
Threshold Detector with
Internal Fixed Hysteresis
VDD
VOUT
VREF = 2.55V
2.75V < VDD < 5.5V
Lithium
Coin Cell
INP
OUT
to Host
GND
Nano-Power Battery Monitor
Teeny™ is a trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
July 2005
M9999-070505
(408) 955-1690
Micrel, Inc.
MIC845
Ordering Information
Part Number
Standard
Marking
Pb-Free
Temperature Range
Package
Marking*
MIC845HBC5
B19
MIC845HYC5
B19
–40° to +85°C
SC-70
MIC845LBC5
B20
MIC845LYC5
B20
–40° to +85°C
SC-70
MIC845NBC5
B21
MIC845NYC5
B21
–40° to +85°C
SC-70
* Note: Underscore on device marking indicates Pb-Free packaging.
Pin Configuration
INP GND NIC
1
3
2
4
OUT
5
VDD
SC-70-5 (C5)
(TOP VIEW)
Pin Description
Pin Number
Pin Name
Pin Function
1
NIC
No Internal Connection. A signal applied to this pin will have no effect
on device operation.
2
GND
Ground
3
INP
Input: Analog input to the comparator. When VINP > VREF+ VHYST, VOUT is
asserted, and the condition is held until VINP < VREF.
4
OUT
Output: Active-high, open-drain output. This output is low when
VINP < VREF, indicating a low voltage input. The output is high when
VINP > VREF + VHYST.
(“N” Version)
OUT
(“H” Version)
OUT
5
July 2005
Output: Active-high, Push-pull output. This output is low when
VINP < VREF, indicating a low voltage condition. The output is high when
VINP > VREF+ VHYST.
(“L” Version)
Output: Active-low, Push-pull output. This output is high when
VINP < VREF, indicating a low voltage condition. The output is low when
VINP > VREF+ VHYST.
VDD
Power Supply (Input): Independent supply input for internal circuitry.
2
M9999-070505
(408) 955-1690
Micrel, Inc.
MIC845
Absolute Maximum Ratings(1)
Operating Ratings(2)
Supply Voltage (VDD) ..............................-0.3V to +6V
Input Voltage (VINP).................................-0.3V to +6V
Output Current (IOUT)......................................... 20mA
Junction Temperature (TJ) .............. –40°C to +125°C
Storage Temperature (Ts)............... –65°C to +150°C
Lead Temperature (soldering, 5 sec.) ..............260°C
ESD Rating(3) ........................................................3kV
Supply voltage (VDD) ........................ +2.75V to +5.5V
Input Voltage............................................... -0.3 to 6V
Ambient Temperature (TA)................ –40°C to +85°C
Junction to Ambient Thermal Resistance:
SC-70 (θJA) ............................................ 450°C/W
Electrical Characteristics
2.75V < VDD < 5.5V; TA = 25°C, Bold values indicate –40°C< TA < +85°C, unless noted.
Parameter
Parameter
Conditions
IDD
Supply Current
No load on output
IINP
Input Leakage Current
VDD = 5.5V, VINP = 0V
.005
10
nA
IINP_PD
Input Leakage Current in power down
VDD = 0V (note 4),
VINP = 5.5V
.005
10
nA
VREF
VREF
–40°C to 85°C
2.50
2.55
2.60
V
VHYST
Comparator Hysteresis
8
25
40
mV
VOUT
Output Voltage, ‘N’
ISINK = 1.6mA, VDD ≥ 2.75V
0.3
V
VOUT
Output Voltage, ‘L’ and ‘H’
ISINK = 1.6mA, VDD ≥ 2.75V
0.3
V
ISOURCE = 500µA,
VDD ≥ 2.75V
tD
Propagation Delay
Min
0.95
× VDD
Typ.
Max
Units
1
3
µA
0.99
× VDD
V
VINP = 2.7V to 2.4V
12
39
µs
VINP = 2.4V to 2.7V
8
26
µs
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model: 1.5k in series with 100pF.
4. VDD is tied to Gnd, not left floating.
July 2005
3
M9999-070505
(408) 955-1690
Micrel, Inc.
MIC845
Typical Characteristics
IDD vs. Temperature
IIN vs. Temperature
1500
800
IDD (nA)
600
1000
VDD = 4.5V
VIN = 0V
500
400
0
-500
200
-1000
0
VDD = 0V
VIN = 4.5V
-200
-40 -20 0
20 40 60
TEMPERATURE (°C)
-2000
-40 -20 0
20 40 60
TEMPERATURE (°C)
80
800
VDD = 3V
VIN = 4.2V
600
IDD (nA)
800
400
200
VDD = 0V
VIN = 4.2V
-200
-40 -20 0
20 40 60
TEMPERATURE (°C)
July 2005
VDD = 0V
VIN = 4.2V
400
600
0
80
IIN vs. Temperature
1200
200
VDD = 4.5V
VIN = 0V
-1500
IDD vs. Temperature
1000
VDD = 0V
VIN = 4.5V
0
VDD = 3V
VIN = 4.2V
-200
-40 -20 0
20 40 60
TEMPERATURE (°C)
80
4
80
M9999-070505
(408) 955-1690
Micrel, Inc.
MIC845
Block Diagrams
VDD
VDD
5
VIN
VTH
3
OUT
VDD
5
VIN
High-Voltage
Detect
INP
VTH
VDD
High-Voltage
Detect
INP
3
OUT
4
4
2.55V
Bandgap
Reference
2.55V
Bandgap
Reference
2
GND
2
GND
MIC845L
MIC845H
VDD
VIN
VTH
VDD
5
High-Voltage
Detect
INP
OUT
4
3
2.55V
Bandgap
Reference
2
GND
MIC845N
VOUT
VOUT
VIN
VIN
VREF + Hysteresis
VREF + Hysteresis
VREF
VREF
Type L
Type H and N
July 2005
5
M9999-070505
(408) 955-1690
Micrel, Inc.
MIC845
there will be no conduction from INP to VDD or any
circuitry internal to MIC845.
Application Information
Output
Input Transients
The MIC845N output is an open-drain MOSFET, so
most applications will require a pull-up resistor. It is
recommended that the value of this resistor not
exceed 470kΩ, otherwise PCB leakages may begin
to dominate and give a false output indication.
MIC845 is inherently immune to very short
negative-going “glitches.” Very brief transients may
exceed the VINP threshold without tripping the output.
As shown in the figure below, the narrower the
transient, the deeper the threshold overdrive that will
be ignored by the MIC845. The graph represents the
typical allowable transient duration for a given
amount of threshold overdrive that will not generate
an output.
The output of “N” type devices may be pulled up as
high as 6V regardless of the IC’s supply voltage,
without damage to the IC.
The “H” and “L” versions of MIC845 have push-pull
output stages, no pull-up resistors are required. The
maximum output voltage of the “H” and “L” versions
is VDD.
16
Input
14
MIC845 has been designed to present an almost
infinite input resistance at its INP pin making it ideal
for monitoring lithium coin cell and back-up batteries.
In applications where the ‘battery low’ voltage is
2.55V, MIC845’s INP pin may be tied directly to the
cell’s positive terminal without any additional
circuitry.
12
10
8
6
4
2
0
0
MIC845’s input may be subjected to voltages as high
as 6V, steady-state, without any adverse effects,
regardless of the IC’s supply voltage. This applies
even if the supply voltage is zero. This permits a
situation wherein the IC’s supply is turned off, but an
input voltage is still present. Under such conditions,
July 2005
Input Transient
Response
6
200 400 600 800 1000
COMPARATOR OVERDRIVE
VREF - VINP (mV)
M9999-070505
(408) 955-1690
Micrel, Inc.
MIC845
Package Information
0.65 (0.0256) BSC
1.35 (0.053) 2.40 (0.094)
1.15 (0.045) 1.80 (0.071)
2.20 (0.087)
1.80 (0.071)
DIMENSIONS:
MM (INCH)
1.00 (0.039) 1.10 (0.043)
0.80 (0.032) 0.80 (0.032)
0.30 (0.012)
0.15 (0.006)
0.10 (0.004)
0.00 (0.000)
0.18 (0.007)
0.10 (0.004)
0.30 (0.012)
0.10 (0.004)
SC-70-5 (C5)
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http:/www.micrel.com
This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is
assumed by Micrel for its use. Micrel reserves the right to change circuitry and specifications at any time without notification to
the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where
malfunction of a product can reasonably be expected to result in personal injury. Life support devices or systems are devices or
systems that (a) are intended for surgical implant into the body or (b) support or sustain life, and whose failure to perform can be
reasonably expected to result in a significant injury to the user. A Purchaser's use or sale of Micrel Products for use in life
support appliances, devices or systems is a Purchaser's own risk and Purchaser agrees to fully indemnify Micrel for any
damages resulting from such use or sale.
© 2005 Micrel, Inc.
July 2005
7
M9999-070505
(408) 955-1690
Similar pages