MAX9646EBS+TG45 Maxim Integrated Products, MAX9646EBS+TG45 Datasheet - Page 7

• Manufacturer Part Number: MAX9646EBS+TG45
• Description: Power Management Development Tools Low-Power Comparator
• Manufacturer: Maxim Integrated Products

Specifications of MAX9646EBS+TG45

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX9644/MAX9645/MAX9646 are extremely small
comparators ideal for compact, low-current, and low-
voltage applications.
The ICs consume only 400nA (typ). The low-voltage
operating capability of the operating current makes
these devices extremely attractive to long-life battery-
operated devices—these applications can now use a
single digital power-supply rail to power the new gener-
ation of microcontrollers (which can be down to 0.9V).
All parts are available in a tiny 4-bump UCSP, which is
only 0.6mm tall and occupies a 1mm x 1mm footprint
and a 5-pin SOT23.
Noninverting inputs are available on the MAX9644/
MAX9646 and inverting inputs are available on the
MAX9645.
The MAX9644/MAX9645/MAX9646 incorporate an inno-
vative input stage architecture that allows their input
voltage to exceed V
the Absolute Maximum Ratings ). This is unlike tradition-
al comparators that have an input ESD diode clamp
between the input and V
voltage to about 0.3V. The ICs architecture maintains a
high input impedance to input signals even when the
device power-supply voltage is completely turned off
(V
power-saving schemes to be easily implemented in
advanced battery-operated devices. On-chip filtering
provides immunity from any RF noise being picked up by
input traces. These devices feature an internal tempera-
ture-compensated, low-power 0.2V reference voltage.
Table 1. How Devices Behave Under Various Input Voltage Conditions
CC
MAX9644
MAX9645
MAX9646
PART
or REF taken to 0V). This greatly benefits flexible
_______________________________________________________________________________________
Low-Power Comparators with Precision
CC
INPUT VOLTAGE CONDITIONS
Detailed Description
by several volts (limited only by
CC
, limiting this maximum over-
Input Stage Circuitry
V
V
V
V
V
V
IN
IN
IN
IN
IN
IN
> 0.2V
< 0.2V
> 0.2V
< 0.2V
> 0.2V
< 0.2V
Reference in 4-Bump UCSP
External pullup resistor pulls output high.
Output asserts low.
Output asserts low.
External pullup resistor pulls output high.
Output asserts high.
Output asserts low.
The MAX9644/MAX9645 have open-drain outputs that
allow them to interface to logic circuitry running from
supply voltages other than the one supplied to the part.
These devices require an external pullup resistor or
current source for proper operation. Many microcon-
troller digital inputs ports can be readily programmed to
include these.
The MAX9646 has a push-pull output stage that can
both sink and source current, eliminating the need for
an external pullup resistor. In this case, the MAX9646
uses the microcontroller’s power supply as V
Place a 0.1µF capacitor between REF or V
GND as close as possible to the device. During a
switching event, all comparators draw a current spike
from their power-supply rails. This current spike is
minimized by the use of an internal break-before-make
design.
The ICs feature internal hysteresis for noise immunity
and glitch-free operation. If additional hysteresis is
needed, an external positive feedback network can be
easily implemented on the MAX9644 and MAX9646 non-
inverting input devices. Additional external hysteresis is
not possible on the MAX9645 because the noninverting
input of the comparator is not externally accessible.
ACTION AT OUTPUT
Applications Information
Output Stage Structure
Hysteresis Operation
Bypassing REF/V
CC
.
CC
and
CC
7