KM4211

Features:

`208A supply current
`35MHz bandwidth
`Fully specified at +2.7V and +5V supplies
`Output voltage range: 0.08V to 4.88V; Vs = +5
`Input voltage range: -0.3V to +3.8V; Vs = +5
`27V/s slew rate
`±8.5mA linear output current
`±13mA short circuit output current
`21nV/Hz input voltage noise
`Directly replaces OPA2350, MAX4132, MAX4281
`Small package options (SOIC-8 and MSOP-8)


Application

·A/D buffer
·Smart card readers
·Active filters
·Keyless entry
·Signal conditioning
·ASCI input devices
·Portable test instruments
·PCMUA cards
·Portable communications
·Bar-code readers
·Portable/battery-powered applications


Specifications

supply voltage ................. .....0 to +6V
maximum junction temperature ....... ..... ..+175
storage temperature range.......... .. -65 to +150
lead temperature (10 sec) ............. ....+260
operating temperature range (recommended)....-40 to +85
input voltage range .......... .... +V_S+0.5V; -V_s-0.5V
internal power dissipation ....... see power derating curves


Description

The KM4211 is a dual ultra-low power, low cost, voltage feedback amplifier. The KM4211 uses only 208A of supply current per amplifier and is designed to operate from 2.5V to 5.5V or ±1.25V to ±2.75V supplies. The input voltage range extends 300mV below the negative rail and 1.2V below the positive rail.

The KM4211 offers high bipolar performance at a low CMOS price. The KM4211 offers superior dynamic performance with a 35MHz small signal bandwidth and 27V/s slew rate. The combination of low power, high bandwidth, and rail-to-rail performance make the KM4211 well suited for battery-powered communication/computing systems.
The KM4112 (single) and KM4121 (single with disable) are also available.

The KM4211 is a single supply, general purpose, voltage-feedback amplifier fabricated on a complementary bipolar process. The KM4211 offers 35MHz unity gain bandwidth, 27V/s slew rate, and only 208A supply current. It features a rail-to-rail output stage and is unity gain stable.

The design utilizes a patent pending topology that provides increased slew rate performance. The common mode input range extends to 300mV below ground and to 1.2V below V . Exceeding these values will not cause phase reversal. However, if the input voltage exceeds the rails by more than 0.5V, the input ESD devices will begin to conduct. The output will stay at the rail during this overdrive condition.

The design uses a Darlington output stage. The out-put stage is short circuit protected and offers "soft" saturation protection that improves recovery time.

The typical circuit schematic is shown in Figure 1.