PHD User Guide
17
4. Outputs
There are 2 types of outputs on the PHD family of displays.
•
Low-side outputs
•
Sensor supply outputs
4.1. PHD28/PHD50/PHD70 Low-side outputs
The PHD family has two low-side outputs, with the following pin assignments:
•
OUTPUT1
through
OUTPUT2
4.1.1.
Low-side output capabilities
The characteristics of the PHD low-side outputs are shown in the following tables.
Frequency input specifications
Item
Min
Nom
Max
Unit
Output current
500
mA
On resistance
550
mΩ
Max. voltage applied to pin
36
V
Current limit in short-to-ground condition
1.0
1.5
1.9
A
Max PWM Frequency
2000
Hz
Pull-down resistance (PHD28/50)
402.4
kΩ
Pull-down resistance (PHD70)
436.5
kΩ
Feedback gain (Vmicro/Vpin) (see note)
3/33
V/V
Feedback max readable voltage
33
V
Feedback cut-off (3dB) frequency
32
Hz
Note:
Vmicro is the voltage at the micro A/D pin, and Vpin is at the external
connector pin. The tolerance of the Vpin measurement using nominal gain is ±0.5 V.
The outputs have analog feedback for error detection.
Low-side output error detection
Driver State
Output Condition
Feedback voltage
Error Detected?
Off
Open
0 V
No
Off
Short-to-battery
Vsw/11
Yes
Off
Short-to-ground
0 V
No
On
Open
0 V
No
On
Short
>Vsw/11 (see note)
Yes
Note: An over-temperature fault results in driver output cycling.