RECEIVER ENAbLE
SP211E
and
SP213E
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
directly to a shared microprocessor data
bus. For the
SP211E,
enable is active low;
that is, ZeroV applied to the ENABLE pin
will enable the receiver outputs. For the
SP213E,
enable is active high; that is, +5V
applied to the ENABLE pin will enable the
receiver outputs.
SP2E
SD
0
0
EN#
0
0
Drivers
Active
Active
Off
Off
SP23E
SD#
0
0
EN
0
0
Drivers
Off
Off
Active
Active
RX -3
Tri-State
Tri-State
Active
Tri-State
RX 4-5
Active
Tr-State
Active
Tri-State
Receivers
Tri-State
Active
Tri-State
Tri-State
Table 2. Shut-down and Wake–Up Truth Tables
POWER UP WITH SD ACTIVE (Charge pump in shutdown mode)
t
0 (POWERUP)
R
OUT
+5V
0V
t
WAIT
DATA VALID
ENABLE
SD
DISABLE
POWER UP WITH SD DISABLED (Charge pump in active mode)
t
0 (POWERUP)
R
OUT
+5V
0V
DATA VALID
t
ENABLE
ENABLE
SD
DISABLE
EXERCISING WAKE–UP FEATURE
t
0 (POWERUP)
R
OUT
+5V
0V
DATA VALID
t
ENABLE
DISABLE
t
WAIT
V
CC
= +5V –10%; T
A
= 25 C
DATA VALID
t
ENABLE
ENABLE
DATA VALID
t
ENABLE
DISABLE
SD
t
WAIT
= 2ms typical, 3ms maximum
t
ENABLE
= 1ms typical, 2ms maximum
Figure 6. Wake–Up Timing
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • 50-668-707 • www.exar.com
SP207E_00_072309
9
EXAR [ EXAR CORPORATION ]
