Data Sheet

AD8233

Rev. 0 | Page 7 of 29

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

TOP VIEW

(BALL SIDE DOWN)

Not to Scale

AD8233

1

A

B

C

D

23

4

BALL A1

INDICATOR

5

GND

REFIN HPSENSE HPDRIVE

SDN

AC/DC

FR

IAOUT

+IN

LOD

RLD SDN REFOUT RLDFB

–IN

OUT

OPAMP– OPAMP+

SW

RLD

Figure 2. Pin Configuration

Table 5. Pin Function Descriptions

Pin No.

Mnemonic

Description

A1

GND

Power Supply Ground.

A2

Power Supply Terminal.

A3

REFIN

Reference Buffer Input. Use REFIN, a high impedance input terminal, to set the level of the reference buffer.

A4

HPSENSE

High-Pass Sense Input for Instrumentation Amplifier. Connect HPSENSE to the junction of R and C that sets the

corner frequency of the dc blocking circuit.

A5

HPDRIVE

High-Pass Driver Output. Connect HPDRIVE to the capacitor in the first high-pass filter. The AD8233 drives this pin

to keep HPSENSE at the same level as the reference voltage.

B1

SDN

Shutdown Control Input. Drive SDN low to enter the low power shutdown mode.

B2

AC/DC

Leads Off Mode Control Input. Drive the AC/DC pin low for dc leads off mode. Drive the AC/DC pin high for ac

leads off mode.

B3

FR

Fast Restore Control Input. Drive FR high to enable fast recovery mode; otherwise, drive it low.

B4

IAOUT

Instrumentation Amplifier Output Terminal.

B5

+IN

Instrumentation Amplifier, Positive Input. +IN is typically connected to the left arm (LA) electrode.

C1

LOD

Leads Off Detection (LOD) Comparator Output.

C2

RLD SDN

Right Leg Drive Shutdown Control Input. Drive RLD SDN low to power down the RLD amplifier.

C3

REFOUT

Reference Buffer Output. The instrumentation amplifier output is referenced to this potential. Use REFOUT as a

virtual ground for any point in the circuit that requires a signal reference.

C4

RLDFB

Right Leg Drive Feedback Input. RLDFB is the feedback terminal for the right leg drive circuit.

C5

−IN

Instrumentation Amplifier, Negative Input. −IN is typically connected to the right arm (RA) electrode.

D1

OUT

Operational Amplifier Output. The fully conditioned heart rate signal is present at this output. OUT can be

connected to the input of an ADC.

D2

OPAMP−

Operational Amplifier Inverting Input.

D3

OPAMP+

Operational Amplifier Noninverting Input.

D4

SW

Fast Restore Switch Terminal. Connect this terminal to the output of the second high-pass filter.

D5

RLD

Right Leg Drive Output. Connect the driven electrode (typically, right leg) to the RLD pin.