MAX9017A Maxim, MAX9017A Datasheet - Page 11

• Manufacturer Part Number: MAX9017A
• Description: The single MAX9015/MAX9016 and dual MAX9017–MAX9020 nanopower comparators in space-saving SOT23 packages feature Beyond-the-Rails™ inputs and are guaranteed to operate down to 1
• Manufacturer: Maxim

Table 1. Battery Applications Using the MAX9015–MAX9020
The MAX9015–MAX9018 feature an on-board 1.24V
±0.5% (±1.45% for the B grade) reference, yet draw an
ultra-low supply current. The MAX9019/MAX9020
(duals without reference) consume just 850nA of supply
current. All devices are guaranteed to operate down to
1.8V supply. Their common-mode input voltage range
extends 200mV beyond-the-rails. An internal 4mV hys-
teresis ensures clean output switching, even with slow-
moving input signals. Large internal output drivers
swing rail-to-rail with up to ±6mA loads (MAX9015/
MAX9017/MAX9019).
The output stage employs a unique design that mini-
mizes supply-current surges while switching, which vir-
tually eliminates the supply glitches typical of many
other comparators. The MAX9015/MAX9017/MAX9019
have a push-pull output stage that sinks as well as
sources current. The MAX9016/MAX9018/MAX9020
have an open-drain output stage that can be pulled
beyond V
versions are ideal for implementing wire-ORed output
logic functions.
The input common-mode voltage ranges extend from
V
at any differential input voltage within these limits. Input
bias current is typically ±150pA at the trip point, if the
input voltage is between the supply rails. Comparator
inputs are protected from overvoltage by internal ESD
protection diodes connected to the supply rails. As the
input voltage exceeds the supply rails, these ESD pro-
tection diodes become forward biased and begin to
conduct increasing input bias current (see the Input
Bias Current vs. Input Bias Voltage graph in the Typical
Operating Characteristics ).
Alkaline (2 cells)
Nickel-cadmium
(2 cells)
Nickel-metal-hydride
(2 cells)
Lithium-ion (1 cell)
EE
- 0.2V to V
BATTERY
TYPE
CC
up to 5.5V above V
CC
SOT23, Dual, Precision, 1.8V, Nanopower
______________________________________________________________________________________
+ 0.2V. These comparators operate
RECHARGEABLE
Detailed Description
Comparators With/Without Reference
Yes
Yes
Yes
No
Input Stage Circuitry
EE
. These open-drain
V
FRESH
(V)
3.0
2.4
2.4
3.6
V
LIFE
END-OF-
1.8
1.8
1.8
2.9
(V)
The MAX9015–MAX9020 feature a unique break-
before-make output stage capable of driving ±8mA
loads rail-to-rail. Many comparators consume orders of
magnitude more current during switching than during
steady-state operation. However, with the MAX9015–
MAX9020 family of comparators, the supply-current
change during an output transition is extremely small.
In the Typical Operating Characteristics , the Supply
Current vs. Output Transition Frequency graphs show
the minimal supply-current increase as the output
switching frequency approaches 1kHz. This character-
istic reduces the need for power-supply filter capaci-
tors to reduce glitches created by comparator
switching currents. In battery-powered applications,
this characteristic results in a substantial increase in
battery life.
The MAX9015–MAX9018s’ internal +1.24V reference
has a typical temperature coefficient of 40ppm/°C over
the full -40°C to +85°C temperature range. The refer-
ence is a very-low-power bandgap cell, with a typical
35kΩ output impedance. REF can source and sink up
to 100nA to external circuitry. For applications needing
increased drive, buffer REF with a low input-bias cur-
rent op amp such as the MAX4162. Most applications
require no REF bypass capacitor. For noisy environ-
ments or fast transients, connect a 1nF to 10nF ceramic
capacitor from REF to GND.
The MAX9015–MAX9020 are ideally suited for use with
most battery-powered systems. Table 1 lists a variety of
battery types, capacities, and approximate operating
times for the MAX9015–MAX9020, assuming nominal
conditions.
CAPACITY,
AA SIZE
(mA-hr)
2000
1000
1000
750
Low-Voltage, Low-Power Operation
Reference (MAX9015–MAX9018)
OPERATING
MAX9015A/
MAX9016A
Applications Information
TIME (hr)
2000k
1000k
1000k
750k
Output Stage Circuitry
OPERATING
MAX9017/
MAX9018
TIME (hr)
1540k
570k
770k
770k
OPERATING
MAX9019/
MAX9020
TIME (hr)
1333k
500k
660k
660k
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