MAXIM MAX13174ECAG+

19-4742; Rev 0; 7/09
+5V Multiprotocol, Pin-Selectable
Cable Terminator
Features
o Supports V.11 and V.35 Termination
o Pin-Selectable Termination
o Pin-Selectable DCE/DTE Support
The MAX13174E contains six pin-selectable, multiprotocol cable termination networks. Each network is capable of terminating V.11 (RS-422, RS-530, RS-530A,
RS-449, V.36, and X.21) with a 100Ω differential load,
V.35 with a T-network load, or V.28 (RS-232) and V.10
(RS-423) with an open-circuit load for use with transceivers having on-chip termination. The termination protocol can be selected by the serial interface cable
wiring or by pin control. The MAX13174E replaces discrete resistor termination networks and expensive
relays required for multiprotocol termination, saving
space and cost.
o Replaces Discrete Resistor Termination Networks
and Expensive Relays
o Available in 24-Pin SSOP Package
o Certified TBR-1 and TBR-2-Compliant Chipset
(NET1 and NET2)—Pending Completion of Testing
Applications
The MAX13174E terminator is ideal to form a complete
+5V cable- or pin-selectable multiprotocol DCE/DTE
interface port when used with the MAX13170E and
MAX13172E transceiver ICs. The MAX13174E terminator can use the V EE power generated by the
MAX13170E charge pump, simplifying system design.
The MAX13174E/MAX13170E/MAX13172E are pinfor-pin compatible with the MXL1344A/MXL1543/
MXL1544/MAX3175.
The MAX13174E is available in a 24-pin SSOP package
and is specified for the 0°C to +70°C commercial temperature range.
Data Networking
PCI Cards
CSU and DSU
Telecommunication Equipment
Data Routers
Data Switches
Ordering Information
PART
TEMP RANGE
PIN-PACKAGE
MAX13174ECAG+
0°C to +70°C
24 SSOP
+Denotes a lead(Pb)-free/RoHS-compliant package.
Pin Configuration appears at end of data sheet.
Typical Operating Circuit
T4
LL
CTS
DSR
R4
R3
R2
DCD
R1
MAX13172E T3
DTR
RTS
T2
T1
RXD
RXC
R3
R2
TXC
R1
MAX13170E T3
SCTE TXD
T2
T1
MAX13174E
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 Direct at 1-888-629-4642,
or visit Maxim's website at www.maxim-ic.com.
1
MAX13174E
General Description
MAX13174E
+5V Multiprotocol, Pin-Selectable
Cable Terminator
ABSOLUTE MAXIMUM RATINGS
(All voltages to GND, unless otherwise noted.)
Supply Voltages
VCC .......................................................................-0.3V to +6V
VEE.....................................................................+0.3V to -7.1V
Logic-Input Voltages
M0, M1, M2, DCE/DTE, LATCH............................-0.3V to +6V
Termination Network Inputs
R_A, R_B, R_C.....................................................-15V to +15V
R_A to R_B (high-impedance state) ................................±14V
R_A to R_B.........................................................................±6V
R_C to R_B (high-impedance state) ..................................±3V
R_A to R_C.........................................................................±3V
R_C to R_A (high-impedance state) ................................±14V
Continuous Power Dissipation (TA = +70°C)
24-Pin SSOP (derate 14.9mW/°C above +70°C) .......1196mW
Junction-to-Case Thermal Resistance (θJC) (Note 1)
24-Pin SSOP..............................................................24.6°C/W
Junction-to-Ambient Thermal Resistance (θJA) (Note 1)
24-Pin SSOP..............................................................66.9°C/W
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: Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a fourlayer board. For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
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 = +4.5V to +5.5V, VEE = -4V to -7.1V, TA = 0°C to +70°C, unless otherwise noted. Typical values are at TA = +25°C, VCC = +5V,
VEE = -5V, unless otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
VCC Operating Range
VCC
4.5
5
5.5
V
VEE Operating Range
VEE
-7.1
-5
-4
V
1
1.88
2.75
V
2.2
6.15
1.34
2.85
VCC POR Rising Threshold
VCC Supply Current
ICC
All inputs connected to GND or VCC, except
no-cable mode
ICC_NOCAB VEE = 0V, M[x] = 1111 (Note 3)
VEE Supply Current
IEE
All inputs connected to GND or VCC, except
no-cable mode
-3.5
-1
mA
mA
TERMINATOR INPUTS
Differential-Mode Impedance
V.35 Mode
-2V ≤ VCM ≤ +2V, all channels (Figure 1)
90
104
110
Ω
Common-Mode Impedance
V.35 Mode
-2V ≤ VCM ≤ +2V, all channels (Figure 2)
135
153
165
Ω
-7V ≤ VCM ≤ +7V, all channels, except nocable mode (Figure 1)
100
104
110
Differential-Mode Impedance
V.11 Mode
High-Impedance Leakage
Current
Ω
-7V ≤ VCM ≤ +7V, all channels, no-cable
mode, VEE = 0V, VAB ≤ 2V (Figure 1)
IZ
-15V ≤ VR_A ≤ +15V
115
-50
+50
µA
Differential Path Enable Time
50
µs
Differential Path Disable Time
300
µs
Common-Mode Path Enable Time
12
µs
Common-Mode Path Disable
2
µs
2
_______________________________________________________________________________________
+5V Multiprotocol, Pin-Selectable
Cable Terminator
(VCC = +4.5V to +5.5V, VEE = -4V to -7.1V, TA = 0°C to +70°C, unless otherwise noted. Typical values are at TA = +25°C, VCC = +5V,
VEE = -5V, unless otherwise noted.) (Note 2)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
LOGIC INPUTS (M0, M1, M2, LATCH, DCE/DTE)
Input High Voltage
VIH
Input Low Voltage
VIL
Logic Input Current
IIN
0.66 x
VCC
VIN = VCC or GND
V
0.33 x
VCC
V
+1
µA
-1
ESD PROTECTION
R_A, R_B to GND
All Other Pins
Human Body Model
±15
Air Gap Discharge IEC 61000-4-2
±10
Contact Discharge IEC 61000-4-2
±6
Human Body Model
±2
kV
kV
Note 2: All parameters tested at a single temperature. Specifications over temperature are guaranteed by design.
Note 3: M[x] is the input bus DCE/DTE, M2, M1, M0.
Typical Operating Characteristics
(VCC = +5V, VEE = -5V, TA = +25°C, unless otherwise noted.)
106
105
VCM = 0V
104
103
102
VCM = -7V
VCM = +7V
101
108
IMPEDANCE (I)
107
109
100
107
106
105
104
10
20
30
40
50
TEMPERATURE (NC)
60
70
108
107
106
105
104
103
103
102
102
101
101
100
100
0
109
IMPEDANCE (I)
108
110
MAX13174E toc02
109
IMPEDANCE (I)
110
MAX13174E toc01
110
V.11 OR V.35 DIFFERENTIAL IMPEDANCE
vs. SUPPLY VOLTAGE (VCC)
V.11 OR V.35 DIFFERENTIAL IMPEDANCE
vs. COMMON-MODE VOLTAGE (VCM)
MAX13174E toc03
V.11 OR V.35 DIFFERENTIAL IMPEDANCE
vs. TEMPERATURE
-7
-5
-3
-1
1
VCM (V)
3
5
7
4.5
4.7
4.9
5.1
5.3
5.5
VCC (V)
_______________________________________________________________________________________
3
MAX13174E
ELECTRICAL CHARACTERISTICS (continued)
Typical Operating Characteristics (continued)
(VCC = +5V, VEE = -5V, TA = +25°C, unless otherwise noted.)
IMPEDANCE (I)
107
106
105
104
103
102
155
VCM = -2V
150
145
MAX13174E toc06
VCM = +2V
160
160
IMPEDANCE (I)
108
165
MAX13174E toc05
109
IMPEDANCE (I)
165
MAX13174E toc04
110
V.35 COMMON-MODE IMPEDANCE
vs. COMMON-MODE VOLTAGE (VCM)
V.35 COMMON-MODE IMPEDANCE
vs. TEMPERATURE
V.11 OR V.35 DIFFERENTIAL IMPEDANCE
vs. SUPPLY VOLTAGE (VEE)
155
150
145
140
140
101
100
135
135
-7
-6
-5
-4
0
10
20
30
40
50
60
-2
70
-1
0
1
2
VEE (V)
TEMPERATURE (NC)
VCM (V)
V.35 COMMON-MODE IMPEDANCE
vs. SUPPLY VOLTAGE (VCC)
V.35 COMMON-MODE IMPEDANCE
vs. SUPPLY VOLTAGE (VEE)
HI-Z MODE SUPPLY CURRENT
vs. TEMPERATURE
VCM = -2V
145
140
900
800
155
150
MAX13174E toc09
VCM = +2V
SUPPLY CURRENT (FA)
150
IMPEDANCE (I)
155
160
1000
MAX13174E toc08
VCM = +2V
160
165
MAX13174E toc07
165
IMPEDANCE (I)
VCM = -2V
145
700
ICC
600
500
400
IEE
300
200
140
100
135
0
135
4.7
4.9
5.1
5.3
5.5
-7
VCC (V)
-6
-5
0
-4
10
5
PHASE (DEGREES)
80
60
40
30
15
MAX13174E toc10
100
20
40
50
V.11 OR V.35 DIFFERENTIAL IMPEDANCE
PHASE vs. FREQUENCY
V.11 OR V.35 DIFFERENTIAL IMPEDANCE
MAGNITUDE vs. FREQUENCY
120
10
TEMPERATURE (NC)
VEE (V)
MAX13174E toc11
4.5
IMPEDANCE (I)
MAX13174E
+5V Multiprotocol, Pin-Selectable
Cable Terminator
0
-5
-10
-15
-20
-25
20
-30
0
-35
0.1
1
10
FREQUENCY (MHz)
4
100
0.1
1
10
FREQUENCY (MHz)
_______________________________________________________________________________________
100
60
70
+5V Multiprotocol, Pin-Selectable
Cable Terminator
PIN
NAME
1
M0
Mode-Select Input (Table 1)
FUNCTION
2
VEE
Negative Supply Voltage (typically connected to VEE of MAX13170E). Bypass to GND with a 0.1µF capacitor.
3
R1C
Load 1, Center Tap
4
R1B
Load 1, Node B
5
R1A
Load 1, Node A
6
R2A
Load 2, Node A
7
R2B
Load 2, Node B
8
R2C
Load 2, Center Tap
9
R3A
Load 3, Node A
10
R3B
Load 3, Node B
Load 3, Center Tap
11
R3C
12, 13
GND
Ground
14
VCC
+5V Supply Voltage. Bypass to GND with a 0.1µF capacitor.
15
R4B
Load 4, Node B
16
R4A
Load 4, Node A
17
R5B
Load 5, Node B
18
R5A
Load 5, Node A
19
R6A
Load 6, Node A
20
R6B
Load 6, Node B
21
LATCH
22
DCE/DTE
23
M2
Mode-Select Input (Table 1)
24
M1
Mode-Select Input (Table 1)
Latch Signal Input. When LATCH is low, the input latches are transparent. When LATCH is high, the data
at the mode-select inputs are latched.
DCE/DTE Mode-Select Input (Table 1)
Detailed Description
The MAX13174E contains six pin-selectable multiprotocol cable termination networks (Figure 3). Each network
is capable of terminating V.11 (RS-422, RS-530,
RS-530A, RS-449, V.36, and X.21) with a 100Ω differential load, V.35 with a T-network load, or V.28 (RS-232)
and V.10 (RS-423) with an open-circuit load for use with
transceivers that have on-chip termination. The termination protocol can be selected by the serial interface
cable wiring or by pin control. The MAX13174E
replaces discrete resistor termination networks and
expensive relays required for multiprotocol termination,
saving space and cost.
The MAX13174E terminator is designed to form a complete +5V cable- or pin-selectable multiprotocol DCE/DTE
interface port when used with the MAX13170E and
MAX13172E transceivers. The MAX13174E terminator
can use the VEE power generated by the MAX13170E
charge pump, simplifying system design. The
MAX13174E/MAX13170E/MAX13172E are functionally
compatible with the MXL1344A/MXL1543/MXL1544/
MAX3175.
Termination Modes
The termination networks in the MAX13174E can be set
to one of three modes: V.11, V.35, or high impedance.
As shown in Figure 4, in V.11 mode, switch S1 is closed
and switch S2 is open, presenting 104Ω across terminals A and B. In V.35 mode, switches S1 and S2 are
both closed, presenting a T-network with 104Ω differential impedance and 153Ω common-mode impedance.
In high-impedance mode, switches S1 and S2 are both
open, presenting a high impedance across terminals A
and B suitable for V.28 and V.10 modes.
_______________________________________________________________________________________
5
MAX13174E
Pin Description
MAX13174E
+5V Multiprotocol, Pin-Selectable
Cable Terminator
A
A
I
R1 = 52Ω
R1 = 52Ω
AMMETER
S1 ON
S1 ON
R3 = 127Ω
R3 = 127Ω
S2 OFF
AMMETER
VDM = ±2V
S2 ON
R2 = 52Ω
I
R2 = 52Ω
VCM = ±2V
B
VCM = ±7V OR ±2V
RCM =
V
RDM = DM
I
Figure 1. V.11 or V.35 Differential Impedance Measurement
1
24
23
22
21
M0
8
11 12
13
1
2
3
5 4
6 7
9 10 16 15 18 17 19 20
M1
4
5
6
DCE/DTE
LATCH
VCC VEE
14
2
Figure 2. V.35 Common-Mode Impedance Measurement
Older multiprotocol interface termination circuits have
been constructed using expensive relays with discrete
resistors, custom cables with built-in termination, or
complex circuit-board configurations to route signals to
the correct termination. The MAX13174E provides a
simple solution to this termination problem. All required
termination configurations are easily cable- or pinselectable using the four mode-control input pins (M0,
M1, M2, and DCE/DTE).
Using the MAX13174E in a Multiprotocol
Serial Interface
Figure 3. Block Diagram
The state of the MAX13174E’s mode-select pins—M0,
M1, M2, and DCE/DTE—determines the mode of each of
the six termination networks. Table 1 shows a cross-reference of termination mode and select pin state for each of
the six termination networks within the MAX13174E.
No-Cable Mode
The MAX13174E enters no-cable mode when the modeselect inputs—M0, M1, and M2—are connected high. In
no-cable mode, all six termination networks are placed
in V.11 mode, with S1 closed and S2 open (Figure 4).
6
B
Applications Information
3
MAX13174E
M2
VCM
I
The MAX13174E terminator is designed to form a complete +5V cable- or pin-selectable multiprotocol
DCE/DTE interface port when used with the
MAX13170E/MAX13172E differential drivers/receivers.
The MAX13174E terminator is designed to use the VEE
power generated by the MAX13171E’s charge pump
and meets all data sheet specifications when connected as illustrated in Figure 5. The mode-selection tables
of all three devices are identical, allowing the M0, M1,
M2, and DCE/DTE pins of each device to be connected
to a single 4-wire control bus. The MAX13170E and
MAX13172E provide internal pullups for the four lines,
_______________________________________________________________________________________
+5V Multiprotocol, Pin-Selectable
Cable Terminator
MAX13174E
Table 1. Termination Mode Select Table
PROTOCOL
DCE/ DTE
M2
M1
M0
R1
R2
R3
R4
R5
R6
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Z
Z
Z
Z
V.35
Z
Z
V.11
Z
Z
Z
Z
V.35
Z
Z
V.11
Z
Z
Z
Z
V.35
Z
Z
V.11
Z
Z
Z
Z
V.35
Z
Z
V.11
Z
Z
Z
Z
Z
Z
Z
V.11
Z
Z
Z
Z
V.35
Z
Z
V.11
Z
V.11
V.11
V.11
V.35
V.11
Z
V.11
Z
Z
Z
Z
Z
Z
Z
V.11
Z
V.11
V.11
V.11
V.35
V.11
Z
V.11
Z
V.11
V.11
V.11
V.35
V.11
Z
V.11
Z
V.11
V.11
V.11
V.35
V.11
Z
V.11
Z
V.11
V.11
V.11
V.35
V.11
Z
V.11
V.10/RS-423
RS-530A
RS-530
X.21
V.35
RS-449/V.36
V.28/RS-232
No Cable
V.10/RS-423
RS-530A
RS-530
X.21
V.35
RS-449/V.36
V.28/RS-232
No Cable
Note: Z indicates high impedance, 1 = high, and 0 = low. Z, V.11, and V.35 refer to termination modes (Figure 4).
A
A
A
MAX13174E
MAX13174E
R1
52Ω
R1
52Ω
S1
CLOSED
S1
CLOSED
R1
52Ω
S1
OPEN
C
C
S2
OPEN
S2
CLOSED
R3
127Ω
S2
OPEN
R3
127Ω
R3
127Ω
R2
52Ω
B
B
(a) V.11
C
R2
52Ω
R2
52Ω
B
MAX13174E
(b) V.35
(c) Z
Figure 4. Termination Modes
forcing them to the logic-high state if they are not
grounded. This allows interface-mode configuration by
simply strapping the appropriate pins to ground in the
interconnect cable.
V.11 Termination
A standard V.11 interface is shown in Figure 6. For highspeed data transmission, the V.11 specification recommends terminating the cable at the receiver with a 100Ω
(min) resistor. The resistor, although not required, prevents reflections from corrupting transmitted data.
_______________________________________________________________________________________
7
C7
100pF
C6
100pF
3
8
C8
100pF
VCC
5V
11
12 13
MAX13174E
14
C3
4.7µF
1
C1
1µF
27
26
CHARGE
PUMP
2
4
25
C4
4.7µF
DTE_TXD/DCE_RXD
5
DTE_SCTE/DCE_RXC
6
T1
T2
7
R1
9
DTE_RXC/DCE_SCTE
R2
10
DTE_RXD/DCE_TXD
LATCH
21
C2
1µF
2
C5
4.7µF
C12
1µF
VEE
5
4
6
7
9 10 16 15 18 17 19 20 22 23 24 1
24
23
22
21
DTE
2
TXD A
14
TXD B
24
SCTE A
11
SCTE B
20
19
15
12
18
17
16
15
17
9
DCE
RXD A
RXD B
RXC A
RXC B
T3
8
DTE_TXC/DCE_TXC
C13
1µF
DCE/DTE
M2
M1
28
3
VCC
M0
MAX13174E
+5V Multiprotocol, Pin-Selectable
Cable Terminator
R3
3
16
7
MAX13170E
M0
M1
13
M2
14
DCE/DTE
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
12
1
SHIELD
DB-25
CONNECTOR
C9
1µF
VCC
C10
1µF
DTE_RTS/DCE_CTS
DTE_DTR/DCE_DSR
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
T1
T2
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
T3
R1
R2
R3
R4
T4
MAX13172E
M0
15
M1
INVERT
13
M2
14
DCE/DTE
11
12
DCE/DTE
M2
M1
M0
Figure 5. Multiprotocol DCE/DTE Port
8
CTS A
CTS B
_______________________________________________________________________________________
LLA
DCD A
DCD B
DTR A
DTR B
RTS A
RTS B
LLA
+5V Multiprotocol, Pin-Selectable
Cable Terminator
GENERATOR
impedance and a 150Ω ±15Ω common-mode impedance. The V.35 driver generates a current output
(±11mA, typ) that develops an output voltage between
440mV and 660mV across the load termination networks.
LOAD
CABLE
RECEIVER
TERMINATION
In Figure 9, the MAX13174E is used to implement the
resistive T-network that is needed to properly terminate
the V.35 receiver. Internal to the MAX13174E, S1 and S2
are closed to connect the T-network resistors to the circuit.
The V.35 specification allows for ±4V of ground difference
between the V.35 generator and V.35 load. The
MAX13174E maintains correct termination impedance
over these conditions.
A′
A
100Ω
MIN
B
B′
C
C′
Figure 6. Typical V.11 Interface
V.35 EMI reduction
In Figure 7, the MAX13174E is used to terminate the
V.11 receiver on the MAX13170E. Internal to the
MAX13174E, S1 is closed and S2 is open to present a
104Ω typical differential resistance and high-Z common-mode impedance. The MAX13170E's internal V.28
termination is disabled by opening S3.
The V.11 specification allows for signals with commonmode variations of ±7V and differential signal amplitudes from 2V to 6V. The MAX13174E maintains
termination impedance between 100Ω and 110Ω over
these conditions.
For applications where EMI reduction is especially
important, the MAX13174E termination networks provide
a pin for shunting common-mode driver currents to
GND. Mismatches between the driver A and B output
propagation delays can create a common-mode disturbance on the cable. This common-mode energy can be
shunted to GND by placing a 100pF capacitor to GND
from the center tap of the T-network termination (R1C,
R2C, and R3C as shown in Figure 5).
V.28 Termination
Most industry-standard V.28 receivers (including the
MAX13170E and MAX13172E) do not require external
termination because the receiver includes an internal
5kΩ termination resistor. When the MAX13174E is
V.35 Termination
Figure 8 shows a standard V.35 interface. The generator
and the load must both present a 100Ω ±10Ω differential
A′
A
MAX13170E
R5
55kΩ
R1
52Ω
R8
5kΩ
MAX13174E
RECEIVER
S3
S1
S2
R6
11kΩ
R3
124Ω
+
1.4V
R7
11kΩ
R2
52Ω
B′
R4
55kΩ
B
S1
S2
C′
GND
Figure 7. V.11 Termination and Internal Resistance Networks
_______________________________________________________________________________________
9
MAX13174E
BALANCED
INTERCONNECTING
CABLE
MAX13174E
+5V Multiprotocol, Pin-Selectable
Cable Terminator
BALANCED
INTERCONNECTING
CABLE
GENERATOR
LOAD
50Ω
CABLE
TERMINATION
A′
A
125Ω
125Ω
50Ω
RECEIVER
50Ω
50Ω
B
B′
C
C′
Figure 8. Typical V.35 Interface
A′
A
MAX13170E
R5
55kΩ
R1
52Ω
R8
5kΩ
MAX13174E
RECEIVER
S3
S1
S2
R6
11kΩ
R3
124Ω
+
1.4V
R7
11kΩ
R2
52Ω
B′
R4
55kΩ
B
S1
S2
C′
GND
Figure 9. V.35 Termination and Internal Resistance Networks
placed in V.28 mode, all six of the termination networks
are placed in a high-Z mode. In high-Z mode, the
MAX13174E termination networks do not interfere with
the MAX13170E's internal 5kΩ termination.
In Figure 10, the MAX13174E and MAX13170E are
placed in V.28 mode. Switches S1 and S2 are opened
on the MAX13174E to place the network in high-Z
mode. Switch S3 is closed on the MAX13170E to
enable the 5kΩ terminating resistor.
10
A Complete X.21 Interface
A complete DTE-to-DCE interface operating in X.21
mode is shown in Figure 11. The MAX13174E terminates the V.11 clock and data signals. The MAX13170E
carries the clock and data signals, and the MAX13172E
carries the control signals. The control signals generally
do not require external termination.
ESD Protection
ESD-protection structures are incorporated on all pins
to protect against electrostatic discharges encountered
during handling and assembly. The differential resistors
______________________________________________________________________________________
+5V Multiprotocol, Pin-Selectable
Cable Terminator
MAX13174E
A′
A
MAX13170E
R5
55kΩ
R1
52Ω
R8
5kΩ
MAX13174E
S1
S2
R6
11kΩ
RECEIVER
S3
R3
124Ω
+
1.4V
R7
11kΩ
R2
52Ω
B′
R4
55kΩ
B
S1
S2
C′
GND
Figure 10. V.28 Termination and Internal Resistance Networks
have extra protection against static electricity. Maxim’s
engineers have developed state-of-the-art structures to
protect these pins against an ESD of ±15kV (Human
Body Model) without damage. The ESD structures withstand high ESD in all states: normal operation, shutdown, and powered down. After an ESD event, the
MAX13174E keeps working without latchup or damage.
ESD protection can be tested in various ways. The
Electrical Characteristics table shows the limits, and
each device is characterized for protection to the following methods:
• Human Body Model
•
Contact Method specified in IEC 61000-4-2
•
Air Gap Discharge Method specified in IEC 61000-4-2
ESD Test Conditions
ESD performance depends on a variety of conditions.
Contact Maxim for a reliability report that documents
test setup, test methodology, and test results.
IEC 61000-4-2
The IEC 61000-4-2 standard covers ESD testing and
the performance of finished equipment. However, it
does not specifically refer to integrated circuits. The
MAX13174E helps equipment designs to meet IEC
61000-4-2 without the need for additional ESD-protection components.
The major difference between tests done using the
Human Body Model and IEC 61000-4-2 is higher peak
current in IEC 61000-4-2 because series resistance is
lower in the IEC 61000-4-2 model. Figure 12c shows
the IEC 61000-4-2 model, and Figure 12d shows the
current waveform for the IEC 61000-4-2 ESD Contact
Discharge test.
Compliance Testing
A European Standard EN 45001 test report for the
MAX13170E, MAX13172E, and MAX13174E chipset will
be available from Maxim upon completion of testing.
Contact Maxim Quality Assurance for a copy of the report.
Human Body Model
Figure 12a shows the Human Body Model, and Figure
12b shows the current waveform it generates when discharged into a low impedance. This model consists of a
100pF capacitor charged to the ESD voltage of interest,
which is then discharged into the test device through a
1.5kΩ resistor.
______________________________________________________________________________________
11
MAX13174E
+5V Multiprotocol, Pin-Selectable
Cable Terminator
DTE
SERIAL
CONTROLLER
MAX13170E
DCE
MAX13174E
MAX13174E
TXD
D1
TXD
SCTE
D2
SCTE
D3
TXC
R1
RXC
R2
RXD
R3
104Ω
104Ω
MAX13170E
SERIAL
CONTROLLER
R3
TXD
R2
SCTE
R1
104Ω
104Ω
104Ω
TXC
D3
TXC
RXC
D2
RXC
RXD
D1
RXD
MAX13172E
MAX13172E
RTS
D1
RTS
R3
RTS
DTR
D2
DTR
R2
DTR
D3
R1
DCD
R1
DCD
D3
DCD
DSR
R2
DSR
D2
DSR
CTS
R3
CTS
D1
CTS
LL
D4
R4
LL
R4
LL
D4
Figure 11. DTE-to-DCE X.21 Interface
12
______________________________________________________________________________________
+5V Multiprotocol, Pin-Selectable
Cable Terminator
RD
1500Ω
IP 100%
90%
DISCHARGE
RESISTANCE
CHARGE-CURRENT
LIMIT RESISTOR
IR
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
AMPS
HIGHVOLTAGE
DC
SOURCE
Cs
100pF
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
36.8%
10%
0
0
RD
330Ω
HIGHVOLTAGE
DC
SOURCE
I
100%
90%
Cs
150pF
IPEAK
DISCHARGE
RESISTANCE
CHARGE-CURRENT
LIMIT RESISTOR
tDL
CURRENT WAVEFORM
Figure 12b. Human Body Current Waveform
Figure 12a. Human Body ESD Test Model
RC
50MΩ TO 100MΩ
TIME
tRL
DEVICE
UNDER
TEST
STORAGE
CAPACITOR
10%
tR = 0.7ns TO 1ns
t
30ns
60ns
Figure 12c. IEC 61000-4-2 ESD Test Model
Figure 12d. IEC 61000-4-2 ESD Generator Current Waveform
Chip Information
Pin Configuration
PROCESS: BiCMOS
TOP VIEW
M0 1
+
24 M1
VEE 2
23 M2
R1C 3
22 DCE/DTE
R1B 4
R1A 5
21 LATCH
MAX13174E
20 R6B
R2A 6
19 R6A
R2B 7
18 R5A
R2C 8
17 R5B
R3A 9
16 R4A
R3B 10
15 R4B
R3C 11
14 VCC
GND 12
13 GND
Package Information
For the latest package outline information and land patterns, go
to www.maxim-ic.com/packages.
PACKAGE TYPE
PACKAGE CODE
DOCUMENT NO.
24 SSOP
A24+3
21-0056
SSOP
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.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 13
© 2009 Maxim Integrated Products
SPRINGER
Maxim is a registered trademark of Maxim Integrated Products, Inc.
MAX13174E
RC
1MΩ