ISL3330_14 Datasheet, PDF (12/25 Pages) Intersil Corporation – 3.3V, ±15kV ESD Protected, Dual Protocol (RS-232/RS-485) Transceivers

ISL3330, ISL3331
Test Circuits and Waveforms (Continued)
V_CC ^RXEN
0V ^A
B
R ^RA
15pF
SIGNAL
GENERATOR
B
0V
+1.5V
0V
t_PLH
t_PHL
-1.5V
V_CC
R_A
1.5V
1.5V
0V
FIGURE 4A. TEST CIRCUIT
FIGURE 4B. MEASUREMENT POINTS
FIGURE 4. RS-485 RECEIVER PROPAGATION DELAY
SIGNAL
GENERATOR
RXEN
A
B
R ^RA
1kΩ
V_CC
15pF
SW ^GND
FOR SHDN TESTS, SWITCH ON AND RXEN L- H SIMULTANEOUSLY
PARAMETER
DEN
B (V)
SW
t_HZ
t_LZ
t_ZH
t_ZL
t_ZH(SHDN)
t_ZL(SHDN)
X
+1.5
GND
X
-1.5
V_CC
X
+1.5
GND
X
-1.5
V_CC
0
+1.5
GND
0
-1.5
V_CC
FIGURE 5A. TEST CIRCUIT
RXEN
t_ZH
t_ZH(SHDN)
R_A
t_ZL
t_ZL(SHDN)
R_A
ENABLED
3V
1.5V
1.5V
0V
t_HZ
OUTPUT HIGH
1.5V
V_OH - 0.5V ^VOH
0V
t_LZ
1.5V
OUTPUT LOW
V_CC
V_OL + 0.5VV_OL
FIGURE 5B. MEASUREMENT POINTS
FIGURE 5. RS-485 RECEIVER ENABLE AND DISABLE TIMES
DEN
V_CC
D_Y,Z
Y, Z
C_L
D
R_L
SIGNAL
GENERATOR
D_Y,Z
1.5V
t_DPHL
OUT (Y,Z)
0V
SKEW = |t_DPHL - t_DPLH|
3V
1.5V
0V
t_DPLH
V_O+
0V
V_O-
FIGURE 6A. TEST CIRCUIT
FIGURE 6B. MEASUREMENT POINTS
FIGURE 6. RS-232 DRIVER PROPAGATION DELAY
V_CC
RXEN
A, B
R
R_A, R_B
SIGNAL
GENERATOR
C_L = 15pF
A, B
50%
t_RPHL
R_A, R_B
SKEW = |t_RPHL - t_RPLH|
50%
3V
50%
0V
t_RPLH
50%
V_OH
V_OL
FIGURE 7A. TEST CIRCUIT
FIGURE 7B. MEASUREMENT POINTS
FIGURE 7. RS-232 RECEIVER PROPAGATION DELAY
12
FN6361.0
May 20, 2008