Data Sheet
October 2001
Dual Differential Transceivers
BTK1A and BTM1A
Features
Driver Features
s
s
Description
The BTK1A and BTM1A devices are dual differential
transceiver circuits that transmit and receive digital
data over balanced transmission lines and are
compatible with Agere Systems Inc. quad differential
drivers and receivers. The dual drivers translate input
TTL logic levels to differential pseudo-ECL output
levels. The dual receivers convert differential input
logic levels to TTL output levels. Each driver/receiver
pair has its own common enable control allowing
serial data and a control clock to be transmitted and
received on a single integrated circuit. The BTK1A
transceiver requires the customer to supply
termination resistors on the circuit board. The
BTM1A transceiver has an internal resistor
termination for both the driver outputs (220
Ω
) and
receiver inputs (110
Ω
), eliminating the need for
external resistors on the circuit board when used with
100
Ω
impedance, twisted-pair (or flat) cable. These
transceivers replace the Agere 41 Series
transceivers.
The powerdown loading characteristics of the
receiver input circuit are approximately 8 k
Ω
relative
to the power supplies; hence, they will not load the
transmission line when the circuit is powered down.
For those circuits with termination resistors, the line
will remain impedance matched when the circuit is
powered down. The driver does not load the line
when it is powered down.
The packaging options that are available for the
dual differential transceivers include a 16-pin DIP; a
16-pin, J-lead SOJ; a 16-pin, gull-wing SOIC; and a
16-pin, narrow-body, gull-wing SOIC.
Two line drivers per package
Logic to convert TTL input logic levels to
differential, pseudo-emitter coupled logic (ECL)
output logic levels
No line loading when V
CC
= 0 V
High output driver for 50
Ω
loads
200 mA short-circuit current (typical)
2.0 ns maximum propagation delay
<0.2 ns output skew (typical)
s
s
s
s
s
Receiver Features
s
s
s
Two line receivers per package
High input impedance
≅
8 k
Ω
Logic that converts differential input logic levels to
transistor-transistor logic (TTL) output logic levels
4.0 ns maximum propagation delay
<0.20 V input sensitivity (typical)
−
1.2 V to
+
7.2 V common-mode range
s
s
s
Common Device Features
s
s
Common enable for each driver/receiver pair
Operating temperature range: –40
°
C to +125
°
C
(wider than the 41 Series)
Single 5.0 V
±
10% supply
400 Mbits/s maximum data rate
Meets enhanced small device interface (ESDI)
standards
Electrostatic discharge (ESD) performance better
than the 41 Series
Lower power requirement than the 41 Series
s
s
s
s
s
Dual Differential Transceivers
BTK1A and BTM1A
Data Sheet
October 2001
Pin Information
RO1
DI1
V
CC
ED
ER
GND
DI2
RO2
1
R1
2
3
D1
4
5
D2
6
7
R2
8
BTK1A
16 RI1
15 RI1
14 DO1
13 DO1
12 DO2
11 DO2
10 RI2
9
RI2
RO1
DI1
V
CC
ED
ER
GND
DI2
RO2
1
R1
2
3
D1
4
5
D2
6
7
R2
8
BTM1A
16 RI1
15 RI1
14 DO1
13 DO1
12 DO2
11 DO2
10 RI2
9
RI2
12-2747.b(F)
Figure 1. Differential Transceiver Logic Diagrams
Table 1. Enable Truth Table
ED
0
1
0
1
ER
0
0
1
1
D1
Active
Disabled
Active
Disabled
D2
Active
Disabled
Active
Disabled
R1
Active
Active
Disabled
Disabled
R2
Active
Active
Disabled
Disabled
Absolute Maximum Ratings
Stresses in excess of the absolute maximum ratings can cause permanent damage to the device. These are
absolute stress ratings only. Functional operation of the device is not implied at these or any other conditions in
excess of those given in the operational sections of the data sheet. Exposure to absolute maximum ratings for
extended periods can adversely affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Power Supply Voltage
Ambient Operating Temperature
Storage Temperature
Symbol
V
CC
T
A
T
stg
Min
—
−
40
−
55
Max
6.5
125
150
Unit
V
°C
°C
2
Agere Systems Inc.
Data Sheet
October 2001
Dual Differential Transceivers
BTK1A and BTM1A
Electrical Characteristics
For variations in electrical characteristics over the temperature range, see Figure 10 on page 10 through Figure 12
on page 11.
Table 3. Power Supply Current Characteristics
T
A
=
−
40 °C to +125 °C, V
CC
= 5 V
±
0.5 V.
Parameter
Power Supply Current (V
CC
= 5.5 V):
All Outputs Disabled:
BTK1A
BTM1A
All Outputs Enabled:
BTK1A
BTM1A
Symbol
Min
Typ
Max
Unit
I
CC
I
CC
I
CC
I
CC
40
80
20
80
65
115
35
115
mA
mA
mA
mA
Third State
These drivers produce pseudo-ECL levels, and the third-state mode is different than the conventional TTL devices.
When a driver is placed in the third state, the bases of the output transistors are pulled low, bringing the outputs
below the active-high and active-low levels. This voltage is typically 2 V for most drivers. In the bidirectional bus
application, the driver of one device, which is in its third state, may be back driven by another driver on the bus
whose voltage in the low state is lower than the third-stated device. This could come about due to differences in the
drivers’ independent power supplies. In this case, the device in the third state will control the line, thus clamping
the line and reducing the signal swing. If the difference voltage between the independent power supplies and the
drivers is small, then this consideration can be ignored. In the typical case, the difference voltage can be as much
as 1 V without significantly affecting the amplitude of the driving signal.
Agere Systems Inc.
3
Dual Differential Transceivers
BTK1A and BTM1A
Data Sheet
October 2001
Electrical Characteristics
(continued)
Table 4. Driver Voltage and Current Characteristics
For variations in output voltage over the temperature range, see Figure 10 and Figure 11. T
A
=
−
40 °C to +125 °C.
Parameter
Output Voltages:
Low*
High*:
Differential Voltage (V
OH
– V
OL
)
Third State, I
OH
= –1.0 mA, V
CC
= 4.5 V
Output Voltages (T
A
= 0 °C to 85 °C):
Low*
High*:
Differential Voltage (V
OH
– V
OL
)
Input Voltages:
Low, V
CC
= 5.5 V:
Data Input
Enable Input
High, V
CC
= 4.5 V
Clamp, V
CC
= 4.5 V, I
I
= –5.0 mA
Short-circuit Output Current, V
CC
= 5.5 V
Input Currents, V
CC
= 5.5 V:
Low, V
I
= 0.4 V
High, V
I
= 2.7 V
Reverse, V
I
= 5.5 V
Output Resistors:
BTM1A
‡
R
O
—
220
—
Ω
Symbol
V
OL
V
OH
V
DIFF
V
OZ
V
OL
V
OH
V
DIFF
V
IL
†
V
IL
‡
V
IL
‡
V
IH
†
V
IK
I
OS
§
I
IL
I
IH
I
IH
Min
V
OH
– 1.4
V
CC
−
1.8
0.65
—
V
OH
– 1.4
V
CC
−
1.5
0.8
—
—
—
2.0
—
–100
—
—
—
Typ
V
OH
−
1.1
V
CC
−
1
1.1
V
OL
−
0.5
V
OH
−
1.1
V
CC
−
1
1.1
—
—
—
—
—
—
—
—
—
Max
V
OH
−
0.65
V
CC
−
0.8
1.4
V
OL
−
0.2
V
OH
−
0.8
V
CC
−
0.8
1.4
0.8
0.8
0.7
—
−
1.0
Unit
V
V
V
V
V
V
V
V
V
V
V
V
mA
µ
A
µ
A
µ
A
—
−
400
20
100
* Values are with terminations as per Figure 7.
† The input levels and difference voltage provide zero noise immunity and should be tested only in a static, noise-free environment.
‡ Test must be performed one lead at a time to prevent damage to the device.
4
Agere Systems Inc.
Data Sheet
October 2001
Dual Differential Transceivers
BTK1A and BTM1A
Electrical Characteristics
(continued)
Table 5. Receiver Voltage and Current Characteristics
For variation in minimum V
OH
and maximum V
OL
over the temperature range, see Figure 10.
T
A
=
−
40 °C to +125 °C.
Parameter
Output Voltages V
CC
= 4.5 V:
Low, I
OL
= 8.0 mA*
High, I
OH
=
−
400
µ
A
Enable Input Voltages:
Low, V
CC
= 5.5 V
High, V
CC
= 4.5 V
Clamp, V
CC
= 4.5 V, I
I
= –5.0 mA
Minimum Differential Input Voltages, V
IH –
V
IL
:
†
−
0.80 V < V
IH
< 7.2 V,
−
1.2 V < V
IL
< 6.8 V
Symbol
V
OL
V
OH
V
IL
*
V
IH
*
V
IK
V
TH
*
V
OFF
I
OZL
I
OZH
I
OS
‡
I
IL
I
IH
I
IH
I
IL
I
IH
R
1
Min
—
2.4
—
2.0
—
—
—
—
–25
—
—
—
Typ
—
—
—
—
—
0.1
Max
0.5
—
0.7
—
−
1.0
0.20
Unit
V
V
V
V
V
V
Input Offset Voltage
Output Currents, V
CC
= 5.5 V:
Off-state (high Z), V
O
= 0.4 V
Off-state (high Z), V
O
= 2.4 V
Short Circuit
Enable Input Currents, V
CC
= 5.5 V:
Low, V
IN
= 0.4 V
High, V
IN
= 2.7 V
Reverse, V
IN
= 5.5 V
Differential Input Currents, (BTK1A):
Low, V
IN
= –1.2 V
High, V
IN
= 7.2 V
Differential Input Impedance (BTM1A):
Connected Between RI and RI
0.03
—
—
—
—
—
—
0.05
–20
20
–100
V
µA
µA
mA
µA
µA
µA
mA
mA
Ω
–400
20
100
−
1.0
—
—
—
—
—
110
1.0
—
* The input levels and difference voltage provide zero noise immunity and should be tested only in a static, noise-free environment.
† Outputs of unused receivers assume a logic 1 level when the inputs are left open. (It is recommended that all unused positive inputs
be tied to the positive power supply. No external series resistor is required.)
‡ Test must be performed one lead at a time to prevent damage to the device.
Agere Systems Inc.
5
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