AD8233 Datasheet, PDF (8/30 Pages) Analog Devices – Fitness and activity heart rate monitors

Data Sheet
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
BALL A1
INDICATOR
1
GND
A
AD8233
2
3
4
5
+V_S REFIN HPSENSE HPDRIVE
SDN AC/DC
FR
IAOUT
+IN
B
LOD RLD SDN REFOUT RLDFB –IN
C
OUT OPAMP– OPAMP+ SW
RLD
D
TOP VIEW
(BALL SIDE DOWN)
Not to Scale
Figure 2. Pin Configuration
AD8233
Table 5. Pin Function Descriptions
Pin No. Mnemonic Description
A1
GND
Power Supply Ground.
A2
+VS
A3
REFIN
Power Supply Terminal.
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.
Rev. 0 | Page 7 of 29