MB40578
V CCA
V INA
Figure 2 Analog Input Equivalent Circuit
V CCA
V INA
C INA
VD
I BIAS
R INA
A.GND
A.GND
V RB
X255 Circuits
CINA: Non-linear Emitter-follower Junction Capacitance
RINA: Linear Resistance Model for Input Current Transition by Comparator Switching:
Infinite value for VIN < VRB or when CLK = High
VRB: Voltage at VRB terminal
IBIAS: Constant Input Bias Current
VD: The base-collector junction diode of emitter-follower transistor.
Figure 3 Digital Input Equivalent
V CCA
25 kΩ
3.1 kΩ 25 kΩ
2.1 kΩ
Figure 4 Load Circuit for Output Buffer
Measurement
point
V CCD
RL
To Output pin
Input
CL
V REF=1.4 V
A.GND
D.GND
Note RL = 2 kΩ
CL = 15 pF including scope and jig capacitance
Diodes:IN3064 or equivalent
7