MAX9637 Maxim, MAX9637 Datasheet - Page 9

• Manufacturer Part Number: MAX9637
• Description: The MAX9636/MAX9637/MAX9638 are single-supply, CMOS input op amps featuring wide bandwidth at low quiescent current, making them suitable for a broad range of battery-powered applications such as portable medical instruments, portable media players,
• Manufacturer: Maxim

The MAX9636/MAX9637/MAX9638 are single-supply,
CMOS input op amps. They feature wide bandwidth at
low quiescent current, making them suitable for a broad
range of battery-powered applications such as por-
table medical instruments, portable media players, and
smoke detectors. A combination of extremely low input
bias currents, low input current noise, and low input volt-
age noise allows interface to high-impedance sources
such as photodiode and piezoelectric sensors. These
devices are also ideal for general-purpose signal pro-
cessing functions such as filtering and amplification in a
broad range of portable, battery-powered applications.
The devices’ operational common-mode range extends
0.1V beyond the supply rails, allowing for a wide variety
of single-supply applications.
The ICs also feature low quiescent current and a shut-
down mode that greatly reduces quiescent current while
the device is not operational. This makes the device suit-
able for portable applications where power consumption
must be minimized.
The operational amplifiers have parallel-connected n-
and p-channel differential input stages that combine
to accept a common-mode range extending 100mV
beyond the supply rails. The n-channel stage is active
for common-mode input voltages typically greater than
(V
mon-mode input voltages typically less than (V
A small transition region exists, typically V
- 1.2V, during which both pairs are on.
DD
- 1.2V), and the p-channel stage is active for com-
Detailed Description
3V/5V Low-Power, Low-Noise, CMOS,
Rail-to-Rail Input Stage
DD
- 1.4 to V
DD
- 1.4V).
DD
Rail-to-Rail I/O Op Amps
The maximum output voltage swing is load dependent.
However, it is guaranteed to be within 100mV of the
positive rail even with 3mA of load current. To maximize
the output current sourcing capability, these parts do
not come with built-in short-circuit protection. If loads
heavier than 600ω must be driven, then ensure that the
maximum allowable power dissipation is not exceeded
(see the Absolute Maximum Ratings section).
This op-amp family features ultra-low 0.1pA (typ) input
bias current and guaranteed maximum current of Q50pA
over -40NC to +85NC when the input common-mode volt-
age is at midrail. For the -40NC to +85NC temperature
range, the variation in the input bias current is small
with changes in the input voltage due to very high input
impedance (in the order of 100GI).
The ICs typically require a power-up time of 18µs.
Supply settling time depends on the supply voltage,
the value of the bypass capacitor, the output imped-
ance of the incoming supply, and any lead resistance or
inductance between components. Op amp settling time
depends primarily on the output voltage and is slew-rate
limited. The output settles in approximately 11.5µs for
V
graph in the Typical Operating Characteristics section).
DD
= 3V and V
OUT
= V
Rail-to-Rail Output Stage
DD
Low Input Bias Current
/2V (see the Power-Up Time
Power-Up Time
9