Datasheet
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THIRD STATE
DRIVER ELECTRICAL CHARACTERISTICS
TB5T1
SLLS589C – NOVEMBER 2003 – REVISED OCTOBER 2007
A TB5T1 driver produces pseudo-ECL levels and has a third state mode, which is different from a conventional
TTL device. When a TB5T1 driver is placed in the third state, the base of the output transistors are pulled low,
bringing the outputs below the active-low level of standard PECL devices. (For example: The TB5T1 low output
level is typically 2.7 V, while the third state noninverting output level is typically 1.2 V.) In a bidirectional,
multipoint bus application, the driver of one device, which is in its third state, can be back driven by another
driver on the bus whose voltage in the low state is lower than the 3-stated device. This could be due to
differences between individual driver's power supplies. In this case, the device in the third state controls the line,
thus clamping the line and reducing the signal swing. If the difference between the driver power supplies is small,
this consideration can be ignored. Again using the TB5T1 driver as an example, a typical supply voltage
difference between separate drivers of > 2 V can exist without significantly affecting the amplitude of the signal.
over operating free-air temperature range unless otherwise noted
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
V
OH
Output high voltage
(1)
V
CC
- 1.8 V
CC
- 1.3 V
CC
- 0.8 V
V
OL
Output low voltage
(1)
V
OH
- 1.4 V
OH
- 1.2 V
OH
- 0.7 V
V
OD
Differential output voltage, |V
OH
- V
OL
| 0.7 1.1 1.4 V
V
OH
Output high voltage
(1)
V
CC
- 1.8 V
CC
- 1.3 V
CC
- 0.8 V
V
OL
Output low voltage
(1)
T
A
= 0C to 85C V
OH
- 1.4 V
OH
- 1.1 V
OH
- 0.5 V
V
OD
Differential output voltage, |V
OH
- V
OL
| 0.5 1.1 1.4 V
V
OC(PP)
Peak-to-peak common-mode output voltage C
L
= 5 pF, See Figure 7 230 600 mV
V
OZH
Third state output high voltage
(1)
DO1, DO2 1.4 1.8 2.2
V
CC
= 4.5 V V
Third state deferential output
V
OZD
V
DOn
- V
DOn
-0.47
(2)
-0.6
voltage
(1)
V
IL
Input low voltage
(3)
V
CC
= 5.5 V 0.8 V
V
IH
Input high voltage V
CC
= 4.5 V 2 V
V
IK
Input clamp voltage V
CC
= 4.5 V, I
I
= -5 mA -1
(2)
V
V
CC
= 5.5 V, V
O
= 0 V -250
(2)
mA
I
OS
Short-circuit output current
(4)
V
CC
= 5.5 V, V
OD
= 0 V 10
(2)
mA
I
IL
Input low current V
CC
= 5.5 V, V
I
= 0.4 V -400
(2)
A
I
IH
Input high current V
CC
= 5.5 V, V
I
= 2.7 V 20 A
I
IH
Input reverse current V
CC
= 5.5 V, V
I
= 5.5 V 100 A
C
IN
Input Capacitance 5 pF
(1) Values are with terminations as per Figure 6 .
(2) This parameter is listed using a magnitude and polarity/direction convention, rather than an algebraic convention, to match the original
Agere data sheet.
(3) The input levels and difference voltage provide no noise immunity and should be tested only in a static, noise-free environment.
(4) Test must be performed one lead at a time to prevent damage to the device. No test circuit attached.
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