MAX3317EEUP+ Maxim Integrated Products, MAX3317EEUP+ Datasheet - Page 8

• Manufacturer Part Number: MAX3317EEUP+
• Description: IC TXRX RS232 460KBPS 20-TSSOP
• Manufacturer: Maxim Integrated Products
• Type: Transceiverr

Specifications of MAX3317EEUP+

• Number Of Drivers/receivers: 2/2
• Protocol: RS232
• Voltage - Supply: 2.25 V ~ 3 V
• Mounting Type: Surface Mount
• Package / Case: 20-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Supply current falls to less than 1µA in shutdown mode
(SHDN = low). When shut down, the device’s charge
pumps are turned off, V+ is pulled down to V
pulled to ground, and the transmitter outputs are disabled
(high impedance). The time required to exit shutdown is
typically 30µs, as shown in Figure 2. Connect SHDN to
V
effect on R_OUT.
2.5V, 1µA, 460kbps,
RS-232-Compatible Transceivers
Table 1. Output Control Truth Table (MAX3318/MAX3319)
X = Don’t care
* INVALID connected to FORCEON
** INVALID connected to FORCEON and FORCEOFF
Table 2. Shutdown and Enable Control
Truth Table (MAX3317)
8
Shutdown (Forced
Off)
Normal Operation
(Forced On)
Normal Operation
(AutoShutdown Plus)
Shutdown
(AutoShutdown Plus)
Normal Operation
Normal Operation
Shutdown
Normal Operation
(AutoShutdown)
Shutdown
(AutoShutdown)
CC
_______________________________________________________________________________________
OPERATION
SHDN
if the shutdown mode is not used; SHDN has no
STATUS
0
0
1
1
EN
0
1
0
1
MAX3317 Shutdown Mode
FORCEON
INVALID**
INVALID**
INVALID*
INVALID*
INVALID*
X
1
0
0
T_OUT
High-Z
High-Z
Active
Active
FORCEOFF
INVALID**
INVALID**
0
1
1
1
1
1
1
R_OUT
High-Z
High-Z
Active
Active
CC
, V- is
VALID RECEIVER
LEVEL
Yes
Yes
No
No
Maxim’s AutoShutdown Plus feature on the MAX3318/
MAX3319 allows the supply current to fall to 1µA. These
devices will enter the AutoShutdown Plus mode if
FORCEOFF is high, FORCEON is low, and they do not
sense a valid signal transition on any receiver or trans-
mitter input for 30 seconds. This may occur if the RS-232
cable is disconnected or if the peripheral transmitters
are turned off, and the UART driving the transmitter
inputs is inactive. The system turns on again when a
valid transition is applied to any RS-232 receiver or
transmitter input. As a result, the system saves power
without changes to the existing BIOS or operating system.
Figure 4a depicts valid and invalid RS-232 receiver volt-
age levels. INVALID indicates the receiver input’s condi-
tion and is independent of FORCEON and FORCEOFF
states. Figure 3 and Table 1 summarize the operating
modes of the MAX3318/MAX3319. FORCEON and
FORCEOFF override AutoShutdown Plus circuitry. When
neither control is asserted, the IC selects between these
states automatically, based on the last receiver or trans-
mitter edge received.
X
X
X
X
X
TRANSMITTER
RECEIVER OR
EDGE WITHIN
30s
Yes
Yes
No
No
X
X
X
X
X
AutoShutdown Plus Mode
T_OUT
High-Z
High-Z
High-Z
High-Z
Active
Active
Active
Active
Active
MAX3318/MAX3319
R_OUT
Active
Active
Active
Active
Active
Active
Active
Active
Active