MAXIM MAX3175CAI

19-1992; Rev 0; 4/01
+5V Multiprotocol, Software-Selectable
Control Transceivers
Features
♦ MXL1544/MAX3175, MXL1543, MXL1344A Chipset
Is Pin Compatible with LTC1544, LTC1543,
LTC1344A Chipset
♦ Chipset Operates from a Single +5V Supply
♦ Software-Selectable DCE/DTE
♦ Supports V.28 (RS-232), V.10/V.11 (RS-449/V.36,
EIA-530, EIA-530A, X.21, RS-423) Protocols
♦ Flow-Through Pin Configuration
♦ True Fail-Safe Operation
♦ Low 0.5µA Shutdown Current (No-Cable Mode)
♦ 10µs Receiver Input Deglitching (MAX3175 Only)
♦ TUV-Certified NET1/NET2 and TBR1/TBR2
Compliant
Applications
Ordering Information
Data Networking
CSU and DSU
PART
MXL1544CAI
MAX3175CAI
Data Routers
Switches
PCI Cards
TEMP. RANGE
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
28 SSOP
28 SSOP
Pin Configuration appears at end of data sheet.
Telecommunication Equipment
Typical Operating Circuit
D4
LL
CTS
DSR
R4
R3
R2
R1
MXL1544
MAX3175
DCD
DTR
RTS
D3
D2
D1
RXD
RXC
R3
R2
TXC
R1
MXL1543
D3
SCTE TXD
D2
D1
MXL1344A
18
13 5 10 8
22 6
23 20 19 4
1
7
16 3
9 17
12 15 11 24 14 2
TXD A (103)
TXD B
SCTE A (113)
SCTE B
TXC A (114)
TXC B
RXC A (115)
RXC B
RXD A (104)
RXD B
SG (102)
SHIELD (101)
RTS A (105)
RTS B
DTR A (108)
DTR B
DCD A (107)
DCD B
DSR A (109)
DSR B
CTS A (106)
CTS B
LL A (141)
DB-25 CONNECTOR
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MXL1544/MAX3175
General Description
The MXL1544/MAX3175 are four-driver/four-receiver
multiprotocol transceivers that operate from a single
+5V supply in conjunction with the MXL1543. The
MXL1544/MAX3175, along with the MXL1543 and
MXL1344A, form a complete software-selectable data
terminal equipment (DTE) or data communication
equipment (DCE) interface port that supports the V.28
(RS-232), V.10/V.11 (RS-449/V.36, EIA-530, EIA-530A,
X.21, RS-423), and V.35 protocols. The MXL1544/
MAX3175 transceivers carry serial interface control signaling, while the MXL1543 carries the high-speed clock
and data signals. Typically, the MXL1543 is terminated
using the MXL1344A. The MAX3175 is identical to the
MXL1544 except for the addition of a 10µs (typ) glitch
rejection circuit at the receiver inputs. The MXL1544/
MAX3175 are available in 28-pin SSOP packages.
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
ABSOLUTE MAXIMUM RATINGS
All Voltages to GND Unless Otherwise Noted
Supply Voltages
VCC .......................................................................-0.3V to +6V
VDD ....................................................................-0.3V to +7.2V
VEE........................................................................+0.3V to -7V
VDD to VEE (Note 1)............................................................13V
Logic Input Voltage
M0, M1, M2, DCE/DTE, INVERT, T_IN..................-0.3V to +6V
Logic Output Voltage
R_OUT ....................................................-0.3V to (VCC + 0.3V)
Transmitter Outputs
T_OUT_, T_OUT_/R_IN........................................-15V to +15V
Short-Circuit Duration.............................................Continuous
Receiver Inputs
R_IN_, T_OUT_/R_IN_ .........................................-15V to +15V
Continuous Power Dissipation (TA = +70°C)
28-Pin SSOP (derate 11.1mW/°C above +70°C) .........889mW
Operating Temperature Range...............................0°C to +70°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Note 1: VDD and VEE- can have maximum magnitude of 7.2V and 7V, respectively, but their difference cannot exceed 13V.
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(VCC = +5V, VDD = +6.8V, VEE = -5.6V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
POWER SUPPLIES
VCC Supply Current (DCE
Mode) (Digital Inputs = GND or
VCC) (Transmitters Outputs
Static)
VEE Supply Current (DCE
Mode) (Digital Inputs = GND
or VCC) (Transmitters Outputs
Static)
VDD Supply Current (DCE
Mode) (Digital Inputs = GND or
VCC) (Transmitters Outputs
Static)
Internal Power Dissipation
(DCE Mode)
ICC
RS-530, RS-530A, X.21, no load
2.7
RS-530, RS-530A, X.21, full load
95
120
V.28, no load
1
2
V.28, full load
IEE
IDD
PD
1
2
No-cable mode, Invert = VCC
0.5
10
RS-530, RS-530A, X.21, no load
2.1
RS-530, X.21, full load
14
RS-530A, full load
25
V.28, no load
1
V.28, full load
12
No-cable mode
0.5
RS-530, RS-530A, X.21, no load
0.6
RS-530, RS-530A, X.21, full load
1
V.28, no load
1
V.28, full load
12
No-cable mode
0.5
RS-530, RS-530A, X.21, full load
300
V.28, full load
54
LOGIC INPUTS (M0, M1, M2, DCE/DTE, INVERT, T1IN, T2IN, T3IN, T4IN)
Input High Voltage
VIH
Input Low Voltage
VIL
T1IN, T2IN, T3IN, T4IN
M0, M1, M2, DCE/DTE, INVERT =
Logic Input Current
IIN
GND
M0, M1, M2, DCE/DTE, INVERT =
VCC
2
µA
mA
µA
mW
0.8
±10
-50
_______________________________________________________________________________________
µA
mA
2.0
-100
mA
-30
±10
V
V
µA
+5V Multiprotocol, Software-Selectable
Control Transceivers
(VCC = +5V, VDD = +6.8V, VEE = -5.6V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
3
4.5
MAX
UNITS
0.8
V
50
mA
LOGIC OUTPUTS (R1OUT, R2OUT, R3OUT, R4OUT)
Output High Voltage
VOH
ISOURCE = 4mA
Output Low Voltage
VOL
ISINK = 4mA
Output Short-Circuit Current
ISC
0 ≤ VOUT ≤ VCC
Output Pullup Current
IL
0.3
-50
VOUT = 0, no-cable mode
V
µA
70
RECEIVER INPUTS
Receiver Glitch Rejection
MAX3175 only
5
10
15
µs
±5
V
0.67 ✕
VODO
V
V.11 TRANSMITTER
Open-Circuit Differential Output
Voltage
VODO
Loaded Differential Output
Voltage
VODL
Open circuit, R = 1.95kΩ (Figure 1)
R = 50Ω (Figure 1), TA = +25°C
0.5 ✕
VODO
±2
R = 50Ω (Figure 1)
Change in Magnitude of Output
Differential Voltage
∆VOD
R = 50Ω (Figure 1)
0.2
V
Common-Mode Output Voltage
VOC
R = 50Ω (Figure 1)
3
V
Change in Magnitude of Output
Common-Mode Voltage
∆VOC
R = 50Ω (Figure 1)
0.2
V
VOUT = GND
150
mA
±1
±100
µA
15
25
ns
Short-Circuit Current
Output Leakage Current
ISC
IZ
-0.25V < VOUT < +0.25V, power-off or nocable mode
Rise or Fall Time
tr, tf
R = 50Ω (Figures 2, 5)
Transmitter Input to Output
tPHL,
tPLH
R = 50Ω (Figures 2, 5)
50
75
ns
Data Skew
|tPHL tPLH|
(Figures 2, 5)
3
12
ns
(Figures 2, 5)
3
Output-to-Output Skew
2
ns
V.11 RECEIVER
Differential Input Voltage
Input Hysteresis
VTH
-7V ≤ VCM ≤ 7V
∆VTH
-7V ≤ VCM ≤ 7V
IIN
-10V ≤VA,B ≤ 10V
Receiver Input Resistance
RIN
-10V ≤ VA,B ≤ 10V
Rise or Fall Time
tr, tf
(Figures 2, 6)
Receiver Input Current
Receiver Input to Output
tPHL,
tPLH
(Figures 2, 6)
Data Skew
|tPHL tPLH|
(Figures 2, 6)
-200
15
15
200
mV
40
mV
±0.66
mA
30
kΩ
15
MXL1544
50
MAX3175
10
MXL1544
4
MAX3175
1
ns
80
ns
µs
16
ns
µs
_______________________________________________________________________________________
3
MXL1544/MAX3175
ELECTRICAL CHARACTERISTICS (continued)
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
ELECTRICAL CHARACTERISTICS (continued)
(VCC = +5V, VDD = +6.8V, VEE = -5.6V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
±6
V
V.10 TRANSMITTER
Open-Circuit Output Voltage
Swing
VO
Output Voltage Swing
VT
Short-Circuit Current
ISC
Output Leakage Current
IZ
RL = 3.9kΩ (Figure 3)
±4
RL = 450Ω (Figure 3)
±3.6
RL = 450Ω (Figure 3), TA = +25°C
0.9 x
VO
V
VO = GND, TA = +25°C
-0.25V < VOUT < +0.25V, power-off
or no-cable mode
±1
±150
mA
±100
µA
Rise or Fall Time
tr, tf
RL = 450Ω, CL = 100pF (Figures 3, 7)
2
µs
Transmitter Input to Output
tPHL,
tPLH
RL = 450Ω, CL = 100pF (Figures 3, 7)
1
µs
V.10 RECEIVER
Differential Threshold Voltage
Input Hysteresis
VTH
-250
∆VTH
25
IIN
-10V ≤ VA ≤ 10V
Receiver Input Impedance
RIN
-10V ≤ VA ≤ 10V
Rise or Fall Time
tr, tf
(Figures 4, 8)
Receiver Input Current
(Figures 4, 8)
tPHL
Data Skew
|tPHL tPLH|
(Figures 4, 8)
mV
50
mV
±0.66
mA
30
kΩ
15
ns
55
ns
MAX3175
10
µs
MXL1544
109
ns
MAX3175
10
µs
MXL1544
60
ns
MAX3175
1
µs
MXL1544
tPLH
Receiver Input to Output
15
250
V.28 TRANSMITTER
Output Voltage Swing
VO
Short-Circuit Current
ISC
Output Leakage Current
Output Slew Rate
Transmitter Input to Output
RL = 3kΩ (Figure 3)
-0.25V ≤ VOUT ≤ +0.25V, power-off or
no-cable mode
SR
RL = 3kΩ, CL = 2500pF (Figures 3, 7)
tPLH
V
±5
±150
mA
±1
±100
µA
30
V/µs
1.5
2.5
1.5
3
1.3
0.8
±6
VO = GND
IZ
tPHL
±7
Open circuit (Figure 3)
4
RL = 3kΩ, CL = 2500pF (Figures 3, 7)
V
µs
V.28 RECEIVER
Input Low Voltage
Input High Voltage
4
VIL
VIH
2.0
Input Hysteresis
VHYS
Input Resistance
RIN
-15V < VIN < +15V
Rise or Fall Time
tr, tf
(Figures 4, 8)
3
1.3
V
V
0.05
0.3
V
5
7
kΩ
15
_______________________________________________________________________________________
ns
+5V Multiprotocol, Software-Selectable
Control Transceivers
(VCC = +5V, VDD = +6.8V, VEE = -5.6V, TA = TMIN to TMAX, unless otherwise noted. Typical values are at TA = +25°C.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
tPLH
Receiver Input to Output
(Figures 4, 8)
tPHL
MIN
TYP
MAX
MXL1544
60
100
MAX3175
10
MXL1544
70
MAX3175
10
UNITS
ns
µs
450
ns
µs
Note 2: MXL1544/MAX3175 are designed to operate with VDD and VEE supplied by the MXL1543 charge pump.
Typical Operating Characteristics
(TA = +25°C, unless otherwise noted.)
V.11 MODE SUPPLY CURRENT (IDD)
vs. DATA RATE
V.11 MODE SUPPLY CURRENT (ICC)
vs. DATA RATE
100
DCE MODE
INVERT = 1
DCE MODE
INVERT = 1
9
8
7
IDD (mA)
6
5
4
40
3
FULL, R = 50Ω
NO LOAD, R = 1.95kΩ
2
20
1
NO LOAD, R = 1.95kΩ
0
0
0.1
1
10
100
1000
1000
10,000
V.28 MODE SUPPLY CURRENT (ICC)
vs. DATA RATE
0.73
MXL1544/MAX3175 toc03
DCE MODE
INVERT = 1
6
5
4
DCE MODE
INVERT = 0
0.72
0.71
ICC (mA)
IEE (mA)
100
V.11 MODE SUPPLY CURRENT (IEE)
vs. DATA RATE
7
2
10
DATA RATE (kbps)
8
3
1
DATA RATE (kbps)
10
9
0.1
10,000
MXL1544/MAX3175 toc04
ICC (mA)
80
MXL1544/MAX3175 toc02
FULL LOAD, R = 50Ω
60
10
MXL1544/MAX3175 toc01
120
0.70
FULL LOAD (RL = 3kΩ,
CL = 2500) AND NO LOAD
0.69
0.68
FULL, R = 50Ω
NO LOAD, R = 1.95kΩ
0.67
0.66
1
0
0.65
0.1
1
10
100
DATA RATE (kbps)
1000
10,000
0
50
100
150
200
250
DATA RATE (kbps)
_______________________________________________________________________________________
5
MXL1544/MAX3175
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
DCE MODE
INVERT = 0
FULL LOAD, RL = 3kΩ,
CL = 2500pF
DCE MODE
INVERT = 0
30
25
IEE (mA)
20
15
10
FULL LOAD, RL = 3kΩ,
CL = 2500pF
10
5
5
NO LOAD
NO LOAD
0
0
0
50
100
150
DATA RATE (kbps)
200
0
250
2
DCE MODE
INVERT = 1
RL = 50Ω
0
-1
-2
200
250
VOUT-
10
8
VOUT+
6
OUTPUT VOLTAGE (V)
MXL1544/MAX3175 toc07
VOUT+
1
150
V.10 LOADED OUTPUT VOLTAGE
vs. TEMPERATURE
-3
4
2
DCE MODE
RL = 450Ω
0
-2
-4
VOUT-
-6
-4
-8
-5
-10
20
30
40
60
70
0
10
20
30
40
50
60
TEMPERATURE (°C)
V.28 LOADED OUTPUT VOLTAGE
vs. TEMPERATURE
V.11 RECEIVER INPUT CURRENT
vs. INPUT VOLTAGE
DCE MODE
RL = 3kΩ
8
50
TEMPERATURE (°C)
VOUT+
6
4
2
0
-2
-4
VOUT-
-6
300
70
MXL1544/MAX3175 toc10
10
10
200
INPUT CURRENT (µA)
0
MXL1544/MAX3175 toc09
DIFFERENTIAL OUTPUT VOLTAGE (V)
5
3
100
DATA RATE (kbps)
V.11 LOADED DIFFERENTIAL OUTPUT
VOLTAGE vs. TEMPERATURE
4
50
MXL1544/MAX3175 toc08
IDD (mA)
20
15
35
MXL1544/MAX3175 toc05
25
MXL1544/MAX3175 toc06
V.28 MODE SUPPLY CURRENT (IEE)
vs. DATA RATE
V.28 MODE SUPPLY CURRENT (IDD)
vs. DATA RATE
OUTPUT VOLTAGE (V)
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
100
0
-100
-200
-8
-10
-300
0
10
20
30
40
50
TEMPERATURE (°C)
6
60
70
-10
-5
0
5
INPUT VOLTAGE (V)
_______________________________________________________________________________________
10
+5V Multiprotocol, Software-Selectable
Control Transceivers
V.28 RECEIVER INPUT CURRENT
vs. INPUT VOLTAGE
V.28 SLEW RATE vs. LOAD CAPACITANCE
2
16
14
1
0
-1
12
SLEW+
10
8
-2
6
-3
4
-4
2
-5
SLEW-
0
-15
-10
-5
0
5
10
15
0
1000
2000
3000
4000
5000
INPUT VOLTAGE (V)
CAPACITANCE (pF)
V.10 TRANSMITTER RISE AND FALL TIME
vs. LOAD CAPACITANCE
MXL1544 LOOPBACK SCOPE PHOTO
V.11 MODE (UNLOADED)
MXL1544/MAX3175 toc14
MXL1544/MAX3175 toc13
3.5
RISE
3.0
RISE/FALL TIME (µs)
MXL1544/MAX3175 toc12
3
SLEW RATE (V/µs)
4
INPUT CURRENT (mA)
18
MXL1544/MAX3175 toc11
5
2.5
FALL
2.0
1.5
TIN
5V/div
TOUT/
RIN
5V/div
ROUT
5V/div
1.0
0.5
0
0
500
1000
1500
2000
2500
3000
4µs/div
CAPACITANCE (pF)
MXL1544 LOOPBACK SCOPE PHOTO
V.10 MODE (LOADED)
MXL1544 LOOPBACK SCOPE PHOTO
V.28 MODE (LOADED)
MXL1544/MAX3175 toc15
MXL1544/MAX3175 toc16
TIN
5V/div
TIN
5V/div
TOUT/
RIN
5V/div
TOUT/
RIN
5V/div
ROUT
5V/div
ROUT
5V/div
4µs/div
4µs/div
_______________________________________________________________________________________
7
MXL1544/MAX3175
Typical Operating Characteristics (continued)
(TA = +25°C, unless otherwise noted.)
+5V Multiprotocol, Software-Selectable
Control Transceivers
MXL1544/MAX3175
Pin Description
8
PIN
NAME
1
VCC
+5V Supply Voltage (±5%). Bypass with a 1µF capacitor to ground.
FUNCTION
2
VDD
Positive Supply Generated by MXL1543. Bypass with a 1µF capacitor to ground.
3
T1IN
Transmitter 1 TTL-Compatible Input
4
T2IN
Transmitter 2 TTL-Compatible Input
5
T3IN
Transmitter 3 TTL-Compatible Input
6
R1OUT
Receiver 1 CMOS Output
7
R2OUT
Receiver 2 CMOS Output
8
R3OUT
9
T4IN
10
R4OUT
11
M0
TTL-Compatible Mode Select Pin with Internal Pullup to VCC
12
M1
TTL-Compatible Mode Select Pin with Internal Pullup to VCC
13
M2
TTL-Compatible Mode Select Pin with Internal Pullup to VCC
14
DCE/DTE
Receiver 3 CMOS Output
Transmitter 4 TTL-Compatible Input
Receiver 4 CMOS Output
TTL-Compatible Input with Internal Pullup to VCC. Logic level high selects DCE interface.
15
INVERT
16
T4OUTA/R4INA
TTL Input with Internal Pullup to VCC. INVERT = HIGH reverses action of DCE/DTE for Channel 4.
17
R3INB
Noninverting Receiver Input
18
R3INA
Inverting Receiver Input
19
R2INB
Noninverting Receiver Input
20
R2INA
Inverting Receiver Input
21
T3OUTB/R1INB
22
T3OUTA/R1INA
23
T2OUTB
Noninverting Transmitter Output
24
T2OUTA
Inverting Transmitter Output
25
T1OUTB
Noninverting Transmitter Output
26
T1OUTA
Inverting Transmitter Output
27
GND
Ground
28
VEE
Negative Supply Generated by MXL1543. Bypass with a 1µF capacitor to ground.
Transmitter Output/Inverting Receiver Input
Noninverting Transmitter Output/Noninverting Receiver Input
Inverting Transmitter Output/Inverting Receiver Input
_______________________________________________________________________________________
+5V Multiprotocol, Software-Selectable
Control Transceivers
D
A
R
VOD
VO
CL
RL
VOC
R
Figure 1. V.11 DC Test Circuit
Figure 3. V.10/V.28 Driver Test Circuit
100pF
D
B
B
D
R
A
R
100Ω
A
A
15pF
15pF
100pF
Figure 2. V.11 AC Test Circuit
Detailed Description
The MXL1544/MAX3175 are four-driver/four-receiver
multiprotocol transceivers that operate from a single
+5V supply and the charge pump from the MXL1543.
The MXL1544/MAX3175, along with the MXL1543 and
MXL1344A, form a complete software-selectable DTE
or DCE interface port that supports the V.28 (RS-232),
V.10/V.11 (RS-449, V.36, EIA-530, EIA-530A, X.21, RS423), and V.35 protocols. The MXL1544 or MAX3175
usually carries the control signals. The MXL1543 carries the high-speed clock and data signals, and the
MXL1344A provides termination for the clock and data
signals.
The MXL1544/MAX3175 feature a 0.5µA no-cable
mode, true fail-safe operation, and thermal shutdown
circuitry. Thermal shutdown protects the drivers against
Figure 4. V.10/V.28 Receiver Test Circuit
excessive power dissipation. When activated, the thermal shutdown circuitry places the driver outputs into a
high-impedance state. The MAX3175 deglitching feature reduces errors in unterminated equipment.
The state of the mode-select pins M0, M1, and M2
determines which serial-interface protocol is selected
(Table 1). The state of the DCE/DTE input determines
whether the transceivers will be configured as a DTE
serial port or a DCE serial port. When the DCE/DTE
input is logic HIGH, driver T3 is activated and receiver
R1 is disabled. When the DCE/DTE input is logic LOW,
driver T3 is disabled and receiver R1 is activated. The
INVERT pin state changes the DCE/DTE functionality
regarding T4 and R4 only. M0, M1, M2, INVERT, and
DCE/DTE are internally pulled up to VCC to ensure logic
HIGH if left unconnected.
_______________________________________________________________________________________
9
MXL1544/MAX3175
Test Circuits
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
Switching Time Waveforms
5V
D
f = 1MHz: tr ≤ 10ns: tf ≤ 10ns
1.5V
0
1.5V
tPLH
tPHL
V0
90%
10%
50%
B-A
-V0
tr
90%
VDIFF = V(B) - V(A)
50%
1/2 V0
10%
tf
A
V0
B
tSKEW
tSKEW
Figure 5. V.11, V.35 Driver Propagation Delays
V0D2
B-A
-V0D2
f = 1MHz: tr ≤ 10ns: tf ≤ 10ns
0
INPUT
0
tPHL
tPLH
V0H
OUTPUT
1.5V
R
1.5V
V0L
Figure 6. V.11, V.35 Receiver Propagation Delays
3V
1.5V
D
0
0
tPHL
tPLH
V0
3V
3V
0
0
A
-3V
-V0
-3V
tr
tf
Figure 7. V.10, V.28 Driver Propagation Delays
VIH
A
VIL
1.7V
1.3V
tPLH
tPHL
V0H
R
V0L
2.4V
0.8V
Figure 8. V.10, V.28 Receiver Propagation Delays
10
______________________________________________________________________________________
+5V Multiprotocol, Software-Selectable
Control Transceivers
Fail-Safe
The MXL1544/MAX3175 guarantee a logic HIGH
receiver output when the receiver inputs are shorted or
open, or when they are connected to a terminated
transmission line with all drivers disabled. The V.11
receiver threshold is set between -200mV and 0mV to
guarantee fail-safe operation. If the differential receiver
input voltage (B - A) is ≥ 0mV, ROUT is logic HIGH. In
the case of a terminated bus with all transmitters disabled, the receiver’s differential input voltage is pulled
to 0 by the termination. With the receiver thresholds of
the MXL1544/MAX3175, this results in ROUT logic
HIGH.
The V.10 receiver threshold is set between -250mV and
0mV. If the V.10 receiver input voltage is less than or
equal to -250mV, ROUT is logic HIGH. The V.28 receiver threshold is set between 0.8V and 2.0V. If the receiver input voltage is less than or equal to 0.8V, ROUT is
logic HIGH. In the case of a terminated bus with transmitters disabled, the receiver’s input voltage is pulled
to 0 by the termination.
Applications Information
Cable-Selectable Mode
A cable-selectable, multiprotocol DTE/DCE interface is
shown in Figure 9. The mode control lines M0, M1, and
DCE/DTE are wired to the DB-25 connector. To select
the serial interface mode, the appropriate combination
of M0, M1, M2, and DCE/DTE are grounded within the
cable wiring. The control lines that are not grounded
are pulled high by the internal pullups on the MXL1543.
The serial interface protocol of the MXL1544/MAX3175
is now selected based on the cable that is connected
to the DB-25 interface.
V.10 (RS-423) Interface
The V.10 interface (Figure 10) is an unbalanced singleended interface capable of driving a 450Ω load. The
V.10 driver generates a minimum VO voltage of ±4V
across A’ and C’ when unloaded and a minimum voltage of 0.9 ✕ V O when loaded with 450Ω. The V.10
receiver has a single-ended input and does not reject
common-mode differences between C and C’. The V.10
receiver input trip threshold is defined between
+250mV and -250mV with input impedance characteristic shown in Figure 11.
The MXL1544/MAX3175 V.10 mode receiver has a differential threshold between -250mV and +250mV. To
ensure that the receiver has proper fail-safe operation
see the Fail-Safe section. To aid in rejecting system
noise, the MXL1544/MAX3175 V.10 receiver has a typical hysteresis of 25mV. Switch S3 in Figure 12 is open
in V.10 mode to disable the V.28 5kΩ termination at the
receiver input. Switch S4 is closed and switch S5 is
open to internally ground the receiver B input.
V.11 (RS-422) Interface
As shown in Figure 13, the V.11 protocol is a fully balanced differential interface. The V.11 driver generates a
minimum of ±2V between nodes A and B when 100Ω
minimum resistance is presented at the load. The V.11
receiver is sensitive to differential signals of ±200mV at
receiver inputs A’ and B’. The V.11 receiver input must
comply with the impedance curve of Figure 11 and
reject common-mode signals developed across the
cable (referenced from C to C’ in Figure 13) of up to
±7V.
The MXL1544/MAX3175 V.11 mode receiver has a differential threshold between -200mV and +200mV. To
ensure that the receiver has proper fail-safe operation;
see the Fail-Safe section. To aid in rejecting system
noise, the MXL1544/MAX3175 V.11 receiver has a typical hysteresis of 15mV. Switch S3 in Figure 14 is open
in V.11 mode to disable the V.28 5kΩ termination at the
inverting receiver input. Because the control signals are
slow (60kbps), 100Ω termination resistance is generally
not required for the MXL1544/MAX3175. The receiver
inputs must also be compliant with the impedance
curve shown in Figure 11.
V.28 (RS-232) Interface
The V.28 interface is an unbalanced single-ended interface (Figure 10). The V.28 generator provides a minimum of ±5V across the 3kΩ load impedance between
A’ and C’. The V.28 receiver has single-ended input.
The MXL1544/MAX3175 V.28 mode receiver has a
threshold between +0.8V and +2.0V. To aid in rejecting
system noise, the MXL1544/MAX3175 V.28 receiver
has a typical hysteresis of 50mV. Switch S3 in Figure 15
is closed in V.28 mode to enable the 5kΩ V.28 termination at the receiver inputs.
No-Cable Mode
The MXL1544/MAX3175 will enter no-cable mode when
the mode-select pins are left unconnected or connected HIGH (M0 = M1 = M2 = 1). In this mode, the multiprotocol drivers and receivers are disabled and the
______________________________________________________________________________________
11
MXL1544/MAX3175
The MXL1544/MAX3175s’ mode can be selected
through software control of the M0, M1, M2, INVERT,
and DCE/DTE inputs. Alternatively, the mode can be
selected by shorting the appropriate combination of
mode control inputs to GND (the inputs left floating will
be internally pulled up to VCC - logic HIGH). If the M0,
M1, and M2 mode inputs are all unconnected, the
MXL1544/MAX3175 will enter no-cable mode.
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
C6
C7 C8
100pF 100pF 100pF
3
8
11
12 13
VCC
5V
MXL1344A
14
25
C4
1µF
DTE_TXD/DCE_RXD
5
DTE_SCTE/DCE_RXC
6
D2
7
R1
9
DTE_RXC/DCE_SCTE
R2
10
DTE_RXD/DCE_TXD
VEE
C12
1µF
5 4
6 7
9 10 16 15 18 17 19 20 22 23 24 1
VCC
DTE
2
TXD A
14
TXD B
24
SCTE A
11
SCTE B
DCE
RXD A
RXD B
RXC A
RXC B
20
19
15
12
TXC A
TXC B
18
17
16
15
17
9
D3
8
DTE_TXC/DCE_TXC
2
C5
4.7µF
24
23
22
21
D1
21
M0
27
26
CHARGE
PUMP
2
4
M1
1
C1
1µF
LATCH
C2
1µF
DCE/DTE
M2
C3
4.7µF
C13
1µF
28
3
VCC
R3
3
16
7
TXC A
TXC B
RXC A SCTE A
RXC B SCTE B
RXD A TXD A
RXD B TXD B
SG
11
NC
M0 MXL1543
12
M1
13
M2
14
DCE/DTE
1
SHIELD
DB-25
CONNECTOR
C9
1µF
VCC
1
C10
1µF
2
3
DTE_RTS/DCE_CTS
4
DTE_DTR/DCE_DSR
5
6
DTE_DCD/DCE_DCD
7
DTE_DSR/DCE_DTR
8
DTE_CTS/DCE_RTS
10
9
11
NC
28
VCC
VEE
VDD
GND
D1
D2
27
C11
1µF
25
DCE/DTE
21
M1
18
M0
4
RTS A CTS A
19 RTS B CTS B
20
DTR A DSR A
23
DTR B DSR B
26
25
24
23
D3
R1
R2
R3
R4
8
DCD A
10
DCD B
6
DSR A
22
DSR B
5
CTS A
13 CTS B
22
21
20
19
18
17
16
D4
M0 MXL1544
MAX3175
12
M1
13
M2
14
15
DCE/DTE INVERT
CABLE WIRING FOR
MODE SELECTION
PIN 18
PIN 7
RS-449. V.36 N.C.
PIN 7
RS-232
MODE
V.35
PIN 21
PIN 7
PIN 7
N.C.
CABLE WIRING FOR
DTE/DCE SELECTION
MODE PIN 25
PIN 7
DTE
N.C.
DCE
Figure 9. Cable-Selectable Multiprotocol DCE/DTE Port with DB-25 Connector
12
______________________________________________________________________________________
DCD A
DCD B
DTR A
DTR B
RTS A
RTS B
+5V Multiprotocol, Software-Selectable
Control Transceivers
MXL1544/MAX3175
UNBALANCED
INTERCONNECTING
CABLE
GENERATOR
LOAD
CABLE
TERMINATION
A
A′
C
C′
RECEIVER
Figure 10. Typical V.10/V.28 Interface
IZ
3.25mA
-3V
-10V
VZ
+10V
+3V
-3.25mA
Figure 11. Receiver Input Impedance Curve
A′
A
MXL1544
MAX3175
R5
30kΩ
R8
5kΩ
R6
10kΩ
RECEIVER
BALANCED
INTERCONNECTING
CABLE
GENERATOR
LOAD
CABLE
RECEIVER
TERMINATION
A′
A
100Ω
MIN
B
B′
C
C′
Figure 13. Typical V.11 Interface
supply current is less than 10µA. The receiver outputs
enter a high-impedance state in no-cable mode, which
allows these output lines to be shared with other receiver outputs (the receiver outputs have an internal pullup
resistor to pull the outputs HIGH if not driven). Also, in
no-cable mode, the transmitter outputs enter a highimpedance state, so these output lines can be shared
with other devices.
S3
Receiver Glitch Rejection
R7
10kΩ
B′
R4
30kΩ
B
S5
C′
GND
S4
To improve operation in an unterminated or otherwise
noisy system, the MAX3175 features 10µs of receiver
input glitch rejection. The glitch-rejection circuitry
blocks the reception of high-frequency noise (tB < 5µs)
while receiving a low-frequency signal (tB >15µs) allowing glitch-free operation in unterminated systems at up
to 60kbps. The MXL1544 does not have this feature
and can be operated at frequencies greater than
60kbps if properly terminated.
Figure 12. V.10 Internal Resistance Network
______________________________________________________________________________________
13
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
A′
A
A′
R8
5kΩ
A
MXL1544
MAX3175
R5
30kΩ
R8
5kΩ
R6
10kΩ
R6
10kΩ
RECEIVER
R7
10kΩ
R7
10kΩ
R4
30kΩ
B
B′
C′
R4
30kΩ
B
C′
GND
GND
Figure 14. V.11 Internal Resistance Networks
DTE vs. DCE Operation
Figure 16 shows a port with one DB-25 connector that
can be configured for either DTE or DCE operation. The
configuration requires separate cables for proper signal routing in DTE or DCE operation. Figure 16 illustrates a DCE or DTE controller-selectable interface. The
DCE/DTE and INVERT inputs switch the port’s mode of
operation (Table 1).
The MXL1543 and MXL1544/MAX3175 can be connected for either DTE or DCE operation in one of two ways:
a dedicated DTE or DCE port with an appropriate gender connector or a port with a connector that can be
configured for DTE or DCE operation by rerouting the
signals to the MXL1543 and MXL1544/MAX3175 using
14
RECEIVER
S3
S3
B′
MXL1544
MAX3175
R5
30kΩ
Figure 15. V.28 Termination and Internal Resistance Network
a dedicated DTE cable or dedicated DCE cable. The
interface mode is selected by logic outputs from the
controller or from jumpers to either VCC or GND on the
mode select pins. A dedicated DCE port using a DB-25
female connector is shown in Figure 17. Figure 18 illustrates a dedicated DTE port using a DB-25 male connector.
______________________________________________________________________________________
+5V Multiprotocol, Software-Selectable
Control Transceivers
M2
M1
M0
DCE/
DTE
INVERT
T1
T2
T3
R1
R2
R3
T4
R4
Not Used
(Default V.11)
0
0
0
0
0
V.11
V.11
Z
V.11
V.11
V.11
Z
V.10
RS-530A
0
0
1
0
0
V.11
V.10
Z
V.11
V.10
V.11
Z
V.10
RS-530
0
1
0
0
0
V.11
V.11
Z
V.11
V.11
V.11
Z
V.10
X.21
0
1
1
0
0
V.11
V.11
Z
V.11
V.11
V.11
Z
V.10
V.35
1
0
0
0
0
V.28
V.28
Z
V.28
V.28
V.28
Z
V.28
RS-449/V.36
1
0
1
0
0
V.11
V.11
Z
V.11
V.11
V.11
Z
V.10
V.28/RS-232
1
1
0
0
0
V.28
V.28
Z
V.28
V.28
V.28
Z
V.28
No Cable
1
1
1
0
0
Z
Z
Z
Z
Z
Z
Z
Z
Not Used
(Default V.11)
0
0
0
0
1
V.11
V.11
Z
V.11
V.11
V.11
V.10
Z
RS-530A
0
0
1
0
1
V.11
V.10
Z
V.11
V.10
V.11
V.10
Z
RS-530
0
1
0
0
1
V.11
V.11
Z
V.11
V.11
V.11
V.10
Z
X.21
0
1
1
0
1
V.11
V.11
Z
V.11
V.11
V.11
V.10
Z
V.35
1
0
0
0
1
V.28
V.28
Z
V.28
V.28
V.28
V.28
Z
RS-449/V.36
1
0
1
0
1
V.11
V.11
Z
V.11
V.11
V.11
V.10
Z
V.28/RS-232
1
1
0
0
1
V.28
V.28
Z
V.28
V.28
V.28
V.28
Z
No Cable
1
1
1
0
1
Z
Z
Z
Z
Z
Z
Z
Z
Not Used
(Default V.11)
0
0
0
1
0
V.11
V.11
V.11
Z
V.11
V.11
V.10
Z
RS-530A
RS-530
X.21
V.35
RS-449/V.36
V.28/RS-232
No Cable
Not Used
(Default V.11)
RS-530A
0
0
0
1
1
1
1
0
1
1
0
0
1
1
1
0
1
0
1
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
V.11
V.11
V.11
V.28
V.11
V.28
Z
V.10
V.11
V.11
V.28
V.11
V.28
Z
V.11
V.11
V.11
V.28
V.11
V.28
Z
Z
Z
Z
Z
Z
Z
Z
V.10
V.11
V.11
V.28
V.11
V.28
Z
V.11
V.11
V.11
V.28
V.11
V.28
Z
V.10
V.10
V.10
V.28
V.10
V.28
Z
Z
Z
Z
Z
Z
Z
Z
0
0
0
1
1
V.11
V.11
V.11
Z
V.11
V.11
Z
V.10
0
0
1
1
1
V.11
V.10
V.11
Z
V.10
V.11
Z
V.10
RS-530
0
1
0
1
1
V.11
V.11
V.11
Z
V.11
V.11
Z
V.10
X.21
0
1
1
1
1
V.11
V.11
V.11
Z
V.11
V.11
Z
V.10
V.35
1
0
0
1
1
V.28
V.28
V.28
Z
V.28
V.28
Z
V.28
PROTOCOL
RS-449/V.36
1
0
1
1
1
V.11
V.11
V.11
Z
V.11
V.11
Z
V.10
V.28/RS-232
1
1
0
1
1
V.28
V.28
V.28
Z
V.28
V.28
Z
V.28
No Cable
1
1
1
1
1
Z
Z
Z
Z
Z
Z
Z
Z
______________________________________________________________________________________
15
MXL1544/MAX3175
Table 1. Mode Select Table
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
C6
C7 C8
100pF 100pF 100pF
3
8
11
VCC
5V
12 13
MXL1344A
14
27
26
CHARGE
PUMP
2
4
25
C4
1µF
DTE_TXD/DCE_RXD
5
DTE_SCTE/DCE_RXC
6
D2
7
5 4
6 7
9 10 16 15 18 17 19 20 22 23 24 1
DTE
2
TXD A
14
TXD B
24
SCTE A
11
SCTE B
15
12
17
9
18
17
16
15
R2
10
DTE_RXD/DCE_TXD
C12
1µF
20
19
R1
9
DTE_RXC/DCE_SCTE
VEE
DCE
RXD A
RXD B
RXC A
RXC B
D3
8
DTE_TXC/DCE_TXC
2
C5
4.7µF
24
23
22
21
D1
21
M0
1
C1
1µF
LATCH
C2
1µF
DCE/DTE
M2
M1
C3
4.7µF
C13
1µF
28
3
VCC
R3
3
16
7
TXC A
TXC B
TXC A
TXC B
RXC A SCTE A
RXC B SCTE B
RXD A TXD A
RXD B TXD B
SG
11
M0 MXL1543
12
M1
13
M2
14
DCE/DTE
1
SHIELD
DB-25
CONNECTOR
C9
1µF
C10
1µF
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
VCC
1
2
3
4
5
DTE_DCD/DCE_DCD
DTE_DSR/DCE_DTR
DTE_CTS/DCE_RTS
DTE_LL/DCE_LL
6
7
8
10
9
28
VCC
VEE
VDD
GND
D1
D2
27
C11
1µF
26
25
24
23
4
RTS A
19 RTS B
20
DTR A
23
DTR B
22
21
20
19
18
17
8
DCD A
10
DCD B
6
DSR A
22
DSR B
5
CTS A
13 CTS B
16
18
DSR A
DSR B
D3
R1
R2
R3
R4
LL A
D4
MXL1544
M0 MAX3175
12
M1
15
13
INVERT
M2
14
DCE/DTE
11
INVERT
DCE/DTE
M2
M1
M0
Figure 16. Controller-Selectable Multiprotocol DCE/DTE Port with DB-25 Connector
16
CTS A
CTS B
______________________________________________________________________________________
DCD A
DCD B
DTR A
DTR B
RTS A
RTS B
LL A
+5V Multiprotocol, Software-Selectable
Control Transceivers
MXL1544/MAX3175
C6
C7 C8
100pF 100pF 100pF
3
8
VCC
5V
11
12 13
MXL1344A
14
27
26
CHARGE
PUMP
2
4
25
C4
1µF
RXD
5
RXC
6
D2
5 4
6 7
9 10 16 15 18 17 19 20 22 23 24 1
VCC
3
RXD A (104)
16
RXD B
17
RXC A (115)
9
RXC B
15
TXC A (114)
12
TXC B
24
SCTE A (113)
11
SCTE B
2
TXD A (103)
14 TXD B
7
SGND (102)
18
17
16
15
R2
10
TXD
VEE
C12
1µF
20
19
R1
9
SCTE
21
D3
8
TXC
2
C5
4.7µF
24
23
22
21
D1
7
LATCH
C2
1µF
M0
1
C1
1µF
VCC
DCE/DTE
M2
M1
C3
4.7µF
C13
1µF
28
3
R3
11
M0 MXL1543
12
M1
13
M2
14
NC
DCE/DTE
C9
1µF
C10
1µF
DSR
1
3
4
5
DCD
DTR
RTS
LL
SHIELD (101)
DB-25
FEMALE
CONNECTOR
VCC
2
CTS
1
6
7
8
10
9
28
VCC
VEE
VDD
GND
D1
D2
27
C11
1µF
26
25
24
23
5 CTS A (106)
13 CTS B
6
DSR A (107)
22
DSR B
22
21
8
DCD A (109)
10
DCD B
20
DTR A (108)
23 DTR B
4
RTS A (105)
19
RTS B
18
LL A (141)
D3
R1
R2
R3
R4
20
19
18
17
16
D4
MXL1544
M0 MAX3175
12
M1
15
INVERT
13
M2
14
NC
DCE/DTE
11
INVERT
M2
M1
M0
Figure 17. Controller-Selectable DCE Port with DB-25 Connector
______________________________________________________________________________________
17
MXL1544/MAX3175
+5V Multiprotocol, Software-Selectable
Control Transceivers
C6
C7 C8
100pF 100pF 100pF
3
8
VCC
5V
11
12 13
MXL1344A
14
27
26
CHARGE
PUMP
2
4
25
C4
1µF
TXD
5
SCTE
6
D1
D2
7
R1
9
RXC
R2
10
RXD
2
C5
4.7µF
VEE
C12
1µF
5 4
6 7
9 10 16 15 18 17 19 20 22 23 24 1
24
23
22
21
2
TXD A (103)
14
TXD B
24
SCTE A (113)
11
SCTE B
20
19
15
12
18
17
16
15
17
9
D3
8
TXC
21
M0
1
C1
1µF
LATCH
C2
1µF
DCE/DTE
M2
M1
C3
4.7µF
C13
1µF
28
3
VCC
R3
3
16
7
TXC A (114)
TXC B
RXC A (115)
RXC B
RXD A (104)
RXD B
SG
11
M0 MXL1543
12
M1
13
M2
14
DCE/DTE
1
SHIELD
DB-25 MALE
CONNECTOR
C9
1µF
C10
1µF
VCC
1
2
RTS
DTR
3
4
5
DCD
DSR
CTS
LL
6
7
8
10
9
28
VCC
VEE
VDD
GND
D1
D2
27
C11
1µF
26
25
24
23
4
RTS A (105)
19 RTS B
20
DTR A (108)
23
DTR B
22
21
20
19
18
17
8
DCD A (109)
10
DCD B
6
DSR A (107)
22
DSR B
5
CTS A (106)
13 CTS B
16
18
D3
R1
R2
R3
R4
LL A (141)
D4
MXL1544
M0 MAX3175
12
15
M1
INVERT
13
M2
14
DCE/DTE
11
INVERT
M2
M1
M0
Figure 18. Controller-Selectable Multiprotocol DTE Port with DB-25 Connector
18
______________________________________________________________________________________
+5V Multiprotocol, Software-Selectable
Control Transceivers
TOP VIEW
VCC 1
28 VEE
VDD 2
27 GND
T1IN 3
26 T1OUTA
T2IN 4
25 T1OUTB
T3IN 5
R1OUT 6
24 T2OUTA
MXL1544
MAX3175
23 T2OUTB
R2OUT 7
22 T3OUTA/R1INA
R3OUT 8
21 T3OUTB/R1INB
T4IN 9
20 R2INA
R4OUT 10
19 R2INB
M0 11
18 R3INA
M1 12
17 R3INB
M2 13
16 T4OUTA/R4INA
DCE/DTE 14
15 INVERT
SSOP
______________________________________________________________________________________
19
MXL1544/MAX3175
Pin Configuration
Chip Information
TRANSISTOR COUNT: 2348
PROCESS: BiCMOS
+5V Multiprotocol, Software-Selectable
Control Transceivers
SSOP.EPS
MXL1544/MAX3175
Package Information
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
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© 2001 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.