SP207EH Datasheet, PDF (8/16 Pages) Sipex Corporation – High Speed 5V High Performance RS232 Transceivers

ENABLE
The SP211EH and SP213EH all feature an
enable input, which allows the receiver outputs
to be either tri–stated or enabled. This can be
especially useful when the receiver is tied di-
rectly to a microprocessor data bus. For the
SP211EH, enable is active low; that is, 0V
applied to the ENABLE pin will enable the
receiver outputs. For the SP213EH, enable is
active high; that is, +5V applied to the ENABLE
pin will enable the receiver outputs.
SP213EH Only Power
SD EN SD EN Up/Down
0 01 1
Up
0 11 0
Up
1 00 1
Down
1 10 0
Down
Table 2. Wake–Up Truth Table
Receiver
Outputs
Enable
Tri–state
Enable
Tri–state
POWER UP WITH SD ACTIVE (Charge pump in shutdown mode)
t_{0 (POWERUP)}
+5V
R_OUT
0V
ENABLE
SD
DISABLE
t_WAIT
DATA VALID
POWER UP WITH SD DISABLED (Charge pump in active mode)
t_{0 (POWERUP)}
+5V
R_OUT
0V
ENABLE
SD
DATA VALID
t_ENABLE
DISABLE
EXERCISING WAKE–UP FEATURE
t_{0 (POWERUP)}
+5V
R_OUT
0V
DATA VALID
DATA VALID
t_ENABLE
t_ENABLE
DATA VALID
t_ENABLE
SD
DISABLE
ENABLE
t_WAIT
V_CC = +5V ±10%; T_A = 25°C
t_WAIT = 2ms typical, 3ms maximum
t_ENABLE = 1ms typical, 2ms maximum
DISABLE
Figure 6. Wake–Up Timing
SP207EHDS/08
SP207EH Series High Performance RS232 Transceivers
8
© Copyright 2000 Sipex Corporation