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WHY5640 TEMPERATURE CONTROLLER
PIN DESCRIPTIONS
Table 1. WHY5640 Temperature Controller Pin Descriptions
PIN
NAME
PIN DESCRIPTION
1
AGND
Analog Ground
. This is internally connected to Pins 11 and 12 (the power supply ground
connections) and eliminates grounds loops for stable operation of the sensor amplifier bridge and
limit current resistors.
2
LIMB
Limit B
. A resistor connected between Pin 2 (LIMB) and Pin 1 (AGND) sets the maximum output
current drawn from the Pin 10 (V
S
) supply input and delivered to Pin 13 (OUTB). This is cooling
current limit when used with NTC sensors.
3
LIMA
Limit A
. A resistor connected between Pin 3 (LIMA) and Pin 1 (AGND) sets the maximum output
current drawn from the Pin 10 (V
S
) supply input and delivered to Pin 9 (OUTA). This is heating current
limit when used with NTC sensors.
4
BUFA
Buffer A
. Connect Pin 4 (BUFA) to Pin 3 (LIMA) of another WHY5640 when operating the devices in
a master/booster configuration.
5
PI
Proportional Gain and Integrator Time Constant
. When using the WHY5640 as a standard PI
controller, connect one end of the proportional gain resistors R
G
and R
L
to Pin 5 (PI). R
L
will also
connect in series with C
L
to Pin 3 (LIMA). R
G
will also connect to Pin 6 (ERR).
6
ERR
Temperature Error Input
. When using the WHY5640 as a standard PI controller, connect one end
of the proportional gain resistor R
G
to Pin 6 (ERR) and the other end to Pin 5 (PI).
7
SENS
Sensor and Setpoint Input
. Pin 7 (SENS) is the common sensor bridge amplifier connection for the
sensor, R
T
, and setpoint, R
S
, resistors.
8
VDD
Control Electronics Supply Input
. Power supply input for the WHY5640’s internal control
electronics. Supply range input for this pin is +5 to +26 VDC.
9
OUTA
Thermoelectric Output A
. Connect Pin 9 (OUTA) to the negative terminal on your thermoelectric
when controlling temperature with Negative Temperature Coefficient thermistors. OUTA provides
the heating current when using a NTC sensor. Connect Pin 9 (OUTA) to the positive thermoelectric
terminal when using Positive Temperature Coefficient RTDs.
10
VS
Power Drive Supply Input
. Provides power to the WHY5640 H-Bridge Power Stage. Supply range
input for this pin is +4.5 to +30 VDC. The maximum current drain on this terminal should not exceed
2.5 A.
11
PGND
Power Drive Supply Ground
. Connect the V
S
power supply ground connection to Pin 11 (PGND).
Pin 11 (PGND) and Pin 12 (CGND) are internally connected.
12
CGND
Control Electronics Supply Ground
. Connect the V
DD
supply ground connection to Pin 12 (CGND).
Pin 12 (CGND) and Pin 11 (PGND) are internally connected.
13
OUTB
Thermoelectric Output B
. Connect Pin 13 (OUTB) to the positive terminal on your thermoelectric
when controlling temperature with Negative Temperature Coefficient thermistors. OUTB provides the
cooling current when using a NTC sensor. Connect Pin 13 (OUTB) to the negative thermoelectric
terminal when using Positive Temperature Coefficient RTDs.
14
BUFB
Buffer B
. Connect Pin 14 (BUFB) to Pin 2 (LIMB) of another WHY5640 when operating the devices
in a master/booster configuration.
NOTE: If you are upgrading from the WHY5640 to the WTC3243: The position of Pin 1 on the WHY5640 is reversed
(or mirrored) relative to the position of Pin 1 on the WTC3243.
