DS8922_04 Datasheet, PDF (4/14 Pages) National Semiconductor (TI) – RS-422 Dual Differential Line Driver and Receiver Pairs

Receiver Switching Characteristics
(Figures 1, 2, 3)
Parameter
Conditions
Min
Typ
T_pLH
CL = 30 pF
12
T_pHL
CL = 30 pF
12
|T_pLH–T _pHL|
CL = 30 pF
0.5
Skew (Channel to Channel) CL = 30 pF
0.5
T_pLZ
T_pHZ
T_pZL
T_pZH
CL = 15 pF S2 Open
15
CL = 15 pF S1 Open
15
CL = 30 pF S2 Open
20
CL = 30 pF S1 Open
20
8922
22.5
22.5
5
3.0
Max
8922A/23A
20
20
3.5
2.0
Units
ns
ns
ns
ns
ns
ns
ns
ns
Driver Switching Characteristics
Parameter
Conditions
Min
Typ
SINGLE ENDED CHARACTERISTICS (Figures 4, 5, 6, 8)
T_pLH
CL = 30 pF
12
T_pHL
CL = 30 pF
12
T_TLH
CL = 30 pF
5
T_THL
CL = 30 pF
5
|T_pLH–T _pHL|
CL = 30 pF
0.5
Skew
CL = 30 pF (Note 5)
0.5
Skew (Channel to Channel)
0.5
T_pLZ
CL = 30 pF
15
T_pHZ
CL = 30 pF
15
T_pZL
CL = 30 pF
20
T_pZH
CL = 30 pF
20
DIFFERENTIAL SWITCHING CHARACTERISTICS (Note 6), (Figure 4)
T_pLH
CL = 30 pF
12
T_pHL
CL = 30 pF
12
|T_pLH–T _pHL|
CL = 30 pF
0.5
8922
Max
8922A/23A
15
15
15
15
10
10
10
10
5
3.5
3.0
2.0
15
15
15
15
6.0
2.75
Units
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Note 1: “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. They are not meant to imply that the device
should be operated at these limits. The Table of “Electrical Characteristics” provides conditions for actual device operation.
Note 2: All currents into device pins are shown as positive values; all currents out of the device are shown as negative; all voltages are referenced to ground unless
otherwise specified. All values shown as max or min are classified on absolute value basis.
Note 3: All typical values are V_CC = 5V, T_A = 25˚C.
Note 4: Only one output at a time should be shorted.
Note 5: Difference between complementary outputs at the 50% point.
Note 6: Differential Delays are defined as calculated results from single ended rise and fall time measurements. This approach in establishing AC performance
specifications has been taken due to limitations of available Automatic Test Equipment (ATE).
The calculated ATE results assume a linear transition between measurement points and are a result of the following equations:
Where:
Tcp = Crossing Point
Tra, Trb, Tfa and Tfb are time measurements with respect to the input.
www.national.com
4