74LVC8T245; 74LVCH8T245
8-bit dual supply translating transceiver; 3-state
Rev. 3 — 12 December 2011
Product data sheet
1. General description
The 74LVC8T245; 74LVCH8T245 are 8-bit dual supply translating transceivers with
3-state outputs that enable bidirectional level translation. They feature two data
input-output ports (pins An and Bn), a direction control input (DIR), an output enable input
(OE) and dual supply pins (VCC(A) and VCC(B)). Both VCC(A) and VCC(B) can be supplied at
any voltage between 1.2 V and 5.5 V making the device suitable for translating between
any of the low voltage nodes (1.2 V, 1.5 V, 1.8 V, 2.5 V, 3.3 V and 5.0 V). Pins An, OE and
DIR are referenced to VCC(A) and pins Bn are referenced to VCC(B). A HIGH on DIR allows
transmission from An to Bn and a LOW on DIR allows transmission from Bn to An. The
output enable input (OE) can be used to disable the outputs so the buses are effectively
isolated.
The devices are fully specified for partial power-down applications using IOFF. The IOFF
circuitry disables the output, preventing any damaging backflow current through the
device when it is powered down. In suspend mode when either VCC(A) or VCC(B) are at
GND level, both A port and B port are in the high-impedance OFF-state.
Active bus hold circuitry in the 74LVCH8T245 holds unused or floating data inputs at a
valid logic level.
2. Features and benefits
Wide supply voltage range:
VCC(A): 1.2 V to 5.5 V
VCC(B): 1.2 V to 5.5 V
High noise immunity
Complies with JEDEC standards:
JESD8-7 (1.2 V to 1.95 V)
JESD8-5 (1.8 V to 2.7 V)
JESD8C (2.7 V to 3.6 V)
JESD36 (4.5 V to 5.5 V)
ESD protection:
HBM JESD22-A114F Class 3A exceeds 4000 V
MM JESD22-A115-B exceeds 200 V
CDM JESD22-C101E exceeds 1000 V
Maximum data rates:
420 Mbps (3.3 V to 5.0 V translation)
210 Mbps (translate to 3.3 V))
140 Mbps (translate to 2.5 V)
75 Mbps (translate to 1.8 V)
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
60 Mbps (translate to 1.5 V)
Suspend mode
Latch-up performance exceeds 100 mA per JESD 78B Class II
24 mA output drive (VCC = 3.0 V)
Inputs accept voltages up to 5.5 V
Low power consumption: 30 A maximum ICC
IOFF circuitry provides partial Power-down mode operation
Multiple package options
Specified from 40 C to +85 C and 40 C to +125 C
3. Ordering information
Table 1.
Ordering information
Type number
Package
74LVC8T245PW
Temperature range
Name
Description
Version
40 C to +125 C
TSSOP24
plastic thin shrink small outline package; 24 leads;
body width 4.4 mm
SOT355-1
40 C to +125 C
DHVQFN24 plastic dual in-line compatible thermal enhanced very SOT815-1
thin quad flat package; no leads; 24 terminals;
body 3.5 5.5 0.85 mm
74LVCH8T245PW
74LVC8T245BQ
74LVCH8T245BQ
4. Functional diagram
B1
B2
21
VCC(A)
OE
DIR
Fig 1.
B3
20
B4
19
B5
18
B6
17
B7
16
B8
15
14
VCC(B)
22
2
3
4
5
6
7
8
9
A1
A2
A3
A4
A5
A6
A7
10
A8
001aai472
Logic symbol
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
2 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
DIR
OE
A1
B1
VCC(B)
VCC(A)
to other seven channels
Fig 2.
001aai473
Logic diagram (one channel)
5. Pinning information
5.1 Pinning
terminal 1
index area
1
74LVC8T245
74LVCH8T245
24 VCC(B)
VCC(A)
74LVC8T245
74LVCH8T245
DIR
2
23 VCC(B)
VCC(A)
1
24 VCC(B)
A1
3
22 OE
DIR
2
23 VCC(B)
A2
4
21 B1
A1
3
22 OE
A3
5
20 B2
A2
4
21 B1
A4
6
19 B3
A3
5
20 B2
A5
7
18 B4
A4
6
19 B3
A6
8
17 B5
A5
7
18 B4
A7
9
A6
8
17 B5
A7
9
16 B6
A8 10
15 B7
GND 11
14 B8
GND 12
13 GND
16 B6
A8 10
15 B7
GND(1)
GND 13
14 B8
GND 12
GND 11
001aak437
Transparent top view
001aak436
(1) This is not a supply pin, the substrate is attached to this
pad using conductive die attach material. There is no
electrical or mechanical requirement to solder this pad
however if it is soldered the solder land should remain
floating or be connected to GND.
Fig 3.
Pin configuration SOT355-1 (TSSOP24)
74LVC_LVCH8T245
Product data sheet
Fig 4.
Pin configuration SOT815-1 (DHVQFN24)
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
3 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
5.2 Pin description
Table 2.
Pin description
Symbol
Pin
Description
VCC(A)
1
supply voltage A (An inputs/outputs, OE and DIR inputs are referenced to VCC(A))
DIR
2
direction control
A1 to A8
3, 4, 5, 6, 7, 8, 9, 10
data input or output
GND[1]
11
ground (0 V)
GND[1]
12
ground (0 V)
GND[1]
13
ground (0 V)
B1 to B8
21, 20, 19, 18, 17, 16, 15, 14 data input or output
OE
22
output enable input (active LOW)
VCC(B)
23
supply voltage B (Bn inputs/outputs are referenced to VCC(B))
VCC(B)
24
supply voltage B (Bn inputs/outputs are referenced to VCC(B))
[1]
All GND pins must be connected to ground (0 V).
6. Functional description
Table 3.
Function table[1]
Input/output[3]
Supply voltage
Input
VCC(A), VCC(B)
OE[2]
DIR[2]
An[2]
Bn[2]
1.2 V to 5.5 V
L
L
An = Bn
input
1.2 V to 5.5 V
L
H
input
Bn = An
1.2 V to 5.5 V
H
X
Z
Z
GND[3]
X
X
Z
Z
[1]
H = HIGH voltage level; L = LOW voltage level; X = don’t care; Z = high-impedance OFF-state.
[2]
The An inputs/outputs, DIR and OE input circuit is referenced to VCC(A); The Bn inputs/outputs circuit is referenced to VCC(B).
[3]
If at least one of VCC(A) or VCC(B) is at GND level, the device goes into suspend mode.
7. Limiting values
Table 4.
Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to GND (ground = 0 V).
Symbol
Parameter
VCC(A)
Min
Max
Unit
supply voltage A
0.5
+6.5
V
VCC(B)
supply voltage B
0.5
+6.5
V
50
-
mA
0.5
+6.5
V
IIK
input clamping current
VI
input voltage
IOK
output clamping current
VO
output voltage
Conditions
VI < 0 V
[1]
50
-
mA
[1][2][3]
0.5
VCCO + 0.5
V
0.5
+6.5
V
-
50
mA
-
100
mA
VO < 0 V
Active mode
Suspend or 3-state mode
[1]
IO
output current
VO = 0 V to VCCO
[2]
ICC
supply current
ICC(A) or ICC(B); per VCC pin
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
4 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
Table 4.
Limiting values …continued
In accordance with the Absolute Maximum Rating System (IEC 60134). Voltages are referenced to GND (ground = 0 V).
Symbol
Parameter
Conditions
Min
Max
Unit
IGND
ground current
per GND pin
100
-
mA
Tstg
storage temperature
65
+150
C
-
500
mW
Tamb = 40 C to +125 C
total power dissipation
Ptot
[4]
[1]
The minimum input voltage ratings and output voltage ratings may be exceeded if the input and output current ratings are observed.
[2]
VCCO is the supply voltage associated with the output port.
[3]
VCCO + 0.5 V should not exceed 6.5 V.
[4]
For TSSOP24 package: Ptot derates linearly at 5.5 mW/K above 60 C.
For DHVQFN24 package: Ptot derates linearly at 4.5 mW/K above 60 C.
8. Recommended operating conditions
Table 5.
Recommended operating conditions
Symbol
Parameter
Conditions
VCC(A)
supply voltage A
VCC(B)
supply voltage B
1.2
5.5
V
VI
input voltage
0
5.5
V
VO
output voltage
0
VCCO
V
0
5.5
V
Active mode
[1]
Suspend or 3-state mode
Tamb
ambient temperature
t/V
input transition rise and fall rate
Min
Max
Unit
1.2
5.5
V
40
+125
C
-
20
ns/V
VCCI = 1.4 V to 1.95 V
-
20
ns/V
VCCI = 2.3 V to 2.7 V
-
20
ns/V
VCCI = 1.2 V
[2]
VCCI = 3 V to 3.6 V
-
10
ns/V
VCCI = 4.5 V to 5.5 V
-
5
ns/V
[1]
VCCO is the supply voltage associated with the output port.
[2]
VCCI is the supply voltage associated with the input port.
9. Static characteristics
Table 6.
Typical static characteristics at Tamb = 25 C
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
VOH
HIGH-level output voltage
Conditions
VI = VIH or VIL
Min
Typ
Max
Unit
-
1.09
-
V
[1]
[1]
IO = 3 mA; VCCO = 1.2 V
VOL
LOW-level output voltage
VI = VIH or VIL
IO = 3 mA; VCCO = 1.2 V
-
0.07
-
V
II
input leakage current
DIR, OE input; VI = 0 V to 5.5 V;
VCCI = 1.2 V to 5.5 V
[2]
-
-
1
A
IBHL
bus hold LOW current
A or B port; VI = 0.42 V; VCCI = 1.2 V
[2]
-
19
-
A
A or B port; VI = 0.78 V; VCCI = 1.2 V
[2]
-
19
-
A
IBHH
bus hold HIGH current
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
5 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
Table 6.
Typical static characteristics at Tamb = 25 C …continued
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
Conditions
Min
Typ
Max
Unit
-
19
-
A
IBHLO
bus hold LOW overdrive
current
A or B port; VCCI = 1.2 V
[2][3]
IBHHO
bus hold HIGH overdrive
current
A or B port; VCCI = 1.2 V
[2][3]
-
19
-
A
IOZ
OFF-state output current
A or B port; VO = 0 V or VCCO;
VCCO = 1.2 V to 5.5 V
[1]
-
-
1
A
suspend mode A port; VO = 0 V or VCCO;
VCC(A) = 5.5 V; VCC(B) = 0 V
[1]
-
-
1
A
suspend mode B port; VO = 0 V or VCCO;
VCC(A) = 0 V; VCC(B) = 5.5 V
[1]
-
-
1
A
A port; VI or VO = 0 V to 5.5 V;
VCC(A) = 0 V; VCC(B) = 1.2 V to 5.5 V
-
-
1
A
B port; VI or VO = 0 V to 5.5 V;
VCC(B) = 0 V; VCC(A) = 1.2 V to 5.5 V
-
-
1
A
IOFF
power-off leakage current
CI
input capacitance
DIR, OE input; VI = 0 V or 3.3 V; VCC(A) = 3.3 V
-
3
-
pF
CI/O
input/output capacitance
A and B port; VO = 3.3 V or 0 V;
VCC(A) = VCC(B) = 3.3 V
-
6.5
-
pF
[1]
VCCO is the supply voltage associated with the output port.
[2]
VCCI is the supply voltage associated with the data input port.
[3]
To guarantee the node switches, an external driver must source/sink at least IBHLO / IBHHO when the input is in the range VIL to VIH.
Table 7.
Static characteristics
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
VIH
HIGH-level
input voltage
40 C to +85 C
Conditions
40 C to +125 C
Unit
Min
Max
Min
Max
VCCI = 1.2 V
0.8VCCI
-
0.8VCCI
-
V
VCCI = 1.4 V to 1.95 V
0.65VCCI
-
0.65VCCI
-
V
[1]
data input
VCCI = 2.3 V to 2.7 V
1.7
-
1.7
-
V
VCCI = 3.0 V to 3.6 V
2.0
-
2.0
-
V
VCCI = 4.5 V to 5.5 V
0.7VCCI
-
0.7VCCI
-
V
DIR, OE input
74LVC_LVCH8T245
Product data sheet
VCCI = 1.2 V
0.8VCC(A)
-
0.8VCC(A)
-
V
VCCI = 1.4 V to 1.95 V
0.65VCC(A)
-
0.65VCC(A)
-
V
VCCI = 2.3 V to 2.7 V
1.7
-
1.7
-
V
VCCI = 3.0 V to 3.6 V
2.0
-
2.0
-
V
VCCI = 4.5 V to 5.5 V
0.7VCC(A)
-
0.7VCC(A)
-
V
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
6 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
Table 7.
Static characteristics …continued
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
40 C to +85 C
Conditions
Min
VIL
LOW-level
input voltage
40 C to +125 C
Max
Min
Unit
Max
[1]
data input
VCCI = 1.2 V
-
0.2VCCI
-
0.2VCCI
V
VCCI = 1.4 V to 1.95 V
-
0.35VCCI
-
0.35VCCI
V
VCCI = 2.3 V to 2.7 V
-
0.7
-
0.7
V
VCCI = 3.0 V to 3.6 V
-
0.8
-
0.8
V
VCCI = 4.5 V to 5.5 V
-
0.3VCCI
-
0.3VCCI
V
VCCI = 1.2 V
-
0.2VCC(A)
-
0.2VCC(A) V
VCCI = 1.4 V to 1.95 V
-
0.35VCC(A)
-
0.35VCC(A) V
DIR, OE input
VOH
HIGH-level
output voltage
VCCI = 2.3 V to 2.7 V
-
0.7
-
0.7
V
VCCI = 3.0 V to 3.6 V
-
0.8
-
0.8
V
VCCI = 4.5 V to 5.5 V
-
0.3VCC(A)
-
VCCO 0.1
-
VCCO 0.1
-
V
IO = 6 mA; VCCO = 1.4 V
1.0
-
1.0
-
V
IO = 8 mA; VCCO = 1.65 V
1.2
-
1.2
-
V
IO = 12 mA; VCCO = 2.3 V
1.9
-
1.9
-
V
IO = 24 mA; VCCO = 3.0 V
2.4
-
2.4
-
V
3.8
-
3.8
-
V
IO = 100 A;
VCCO = 1.2 V to 4.5 V
-
0.1
-
0.1
V
IO = 6 mA; VCCO = 1.4 V
-
0.3
-
0.3
V
IO = 8 mA; VCCO = 1.65 V
-
0.45
-
0.45
V
IO = 12 mA; VCCO = 2.3 V
-
0.3
-
0.3
V
IO = 24 mA; VCCO = 3.0 V
-
0.55
-
0.55
V
IO = 32 mA; VCCO = 4.5 V
-
0.55
-
0.55
V
-
2
-
10
A
15
-
10
-
A
25
-
20
-
A
VI = VIH
IO = 100 A;
VCCO = 1.2 V to 4.5 V
[2]
IO = 32 mA; VCCO = 4.5 V
VOL
LOW-level
output voltage
[2]
VI = VIL
II
input leakage
current
IBHL
bus hold LOW A or B port
current
VI = 0.49 V; VCCI = 1.4 V
DIR, OE input; VI = 0 V to 5.5 V;
VCCI = 1.2 V to 5.5 V
VI = 0.58 V; VCCI = 1.65 V
74LVC_LVCH8T245
Product data sheet
0.3VCC(A) V
[1]
VI = 0.70 V; VCCI = 2.3 V
45
-
45
-
A
VI = 0.80 V; VCCI = 3.0 V
100
-
80
-
A
VI = 1.35 V; VCCI = 4.5 V
100
-
100
-
A
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Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
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74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
Table 7.
Static characteristics …continued
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
IBHH
40 C to +85 C
Conditions
bus hold HIGH A or B port
current
VI = 0.91 V; VCCI = 1.4 V
IOFF
-
10
-
A
-
20
-
A
VI = 1.70 V; VCCI = 2.3 V
45
-
45
-
A
VI = 2.00 V; VCCI = 3.0 V
100
-
80
-
A
100
-
100
-
A
125
-
125
-
A
200
-
200
-
A
VCCI = 2.7 V
300
-
300
-
A
VCCI = 3.6 V
500
-
500
-
A
900
-
900
-
A
125
-
125
-
A
200
-
200
-
A
VCCI = 2.7 V
300
-
300
-
A
VCCI = 3.6 V
500
-
500
-
A
[1][3]
[1][3]
bus hold HIGH A or B port
overdrive
VCCI = 1.6 V
current
VCCI = 1.95 V
power-off
leakage
current
74LVC_LVCH8T245
Product data sheet
Max
25
bus hold LOW A or B port
overdrive
VCCI = 1.6 V
current
VCCI = 1.95 V
OFF-state
output current
Min
15
900
-
900
-
A
A or B port; VO = 0 V or VCCO;
VCCO = 1.2 V to 5.5 V
[2]
-
2
-
10
A
suspend mode A port;
VO = 0 V or VCCO; VCC(A) = 5.5 V;
VCC(B) = 0 V
[2]
-
2
-
10
A
suspend mode B port;
VO = 0 V or VCCO; VCC(A) = 0 V;
VCC(B) = 5.5 V
[2]
-
2
-
10
A
A port; VI or VO = 0 V to 5.5 V;
VCC(A) = 0 V;
VCC(B) = 1.2 V to 5.5 V
-
2
-
10
A
B port; VI or VO = 0 V to 5.5 V;
VCC(B) = 0 V;
VCC(A) = 1.2 V to 5.5 V
-
2
-
10
A
VCCI = 5.5 V
IOZ
Max
VI = 1.07 V; VCCI = 1.65 V
VCCI = 5.5 V
IBHHO
Min
Unit
[1]
VI = 3.15 V; VCCI = 4.5 V
IBHLO
40 C to +125 C
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
8 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
Table 7.
Static characteristics …continued
At recommended operating conditions; voltages are referenced to GND (ground = 0 V).
Symbol Parameter
ICC
supply current
40 C to +85 C
Conditions
40 C to +125 C
Unit
Min
Max
Min
Max
VCC(A), VCC(B) = 1.2 V to 5.5 V
-
15
-
20
A
VCC(A) = 5.5 V; VCC(B) = 0 V
-
15
-
20
A
VCC(A) = 0 V; VCC(B) = 5.5 V
2
-
4
-
A
A port; VI = 0 V or VCCI; IO = 0 A
[1]
B port; VI = 0 V or VCCI; IO = 0 A
-
15
-
20
A
VCC(B) = 0 V; VCC(A) = 5.5 V
2
-
4
-
A
VCC(B) = 5.5 V; VCC(A) = 0 V
-
15
-
20
A
-
25
-
30
A
-
50
-
75
A
VCC(A), VCC(B) = 1.2 V to 5.5 V
A plus B port (ICC(A) + ICC(B));
IO = 0 A; VI = 0 V or VCCI
VCC(A), VCC(B) = 1.2 V to 5.5 V
ICC
additional
per input;
supply current VCC(A), VCC(B) = 3.0 V to 5.5 V
DIR and OE input; DIR or OE
input at VCC(A) 0.6 V;
A port at VCC(A) or GND;
B port = open
A port; A port at VCC(A) 0.6 V;
DIR at VCC(A); B port = open
[4]
-
50
-
75
A
B port; B port at VCC(B) 0.6 V;
DIR at GND; A port = open
[4]
-
50
-
75
A
[1]
VCCI is the supply voltage associated with the data input port.
[2]
VCCO is the supply voltage associated with the output port.
[3]
To guarantee the node switches, an external driver must source/sink at least IBHLO / IBHHO when the input is in the range VIL to VIH.
[4]
For non bus hold parts only (74LVC8T245).
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
9 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
10. Dynamic characteristics
Table 8.
Typical dynamic characteristics at VCC(A) = 1.2 V and Tamb = 25 C[1]
Voltages are referenced to GND (ground = 0 V); for test circuit see Figure 7; for waveforms see Figure 5 and Figure 6.
Symbol Parameter
Conditions
VCC(B)
1.2 V
tpd
tdis
ten
[1]
propagation delay
disable time
enable time
Unit
1.5 V
1.8 V
2.5 V
3.3 V
5.0 V
An to Bn
11.0
8.5
7.4
6.2
5.7
5.4
ns
Bn to An
11.0
10.0
9.5
9.1
8.9
8.9
ns
OE to An
9.5
9.5
9.5
9.5
9.5
9.5
ns
OE to Bn
10.2
8.2
7.8
6.7
7.3
6.4
ns
OE to An
13.5
13.5
13.5
13.5
13.5
13.5
ns
OE to Bn
13.6
10.3
8.9
7.5
7.1
7.0
ns
tpd is the same as tPLH and tPHL; tdis is the same as tPLZ and tPHZ; ten is the same as tPZL and tPZH.
Table 9.
Typical dynamic characteristics at VCC(B) = 1.2 V and Tamb = 25 C[1]
Voltages are referenced to GND (ground = 0 V); for test circuit see Figure 7; for waveforms see Figure 5 and Figure 6.
Symbol Parameter
tpd
tdis
ten
[1]
Conditions
propagation delay
disable time
enable time
VCC(A)
1.2 V
1.5 V
1.8 V
An to Bn
11.0
10.0
9.5
Bn to An
11.0
8.5
7.3
OE to An
9.5
6.8
5.4
OE to Bn
10.2
9.1
8.6
Unit
2.5 V
3.3 V
5.0 V
9.1
8.9
8.8
ns
6.2
5.7
5.4
ns
3.8
4.1
3.1
ns
8.1
7.8
7.8
ns
OE to An
13.5
9.0
6.9
4.8
3.8
3.2
ns
OE to Bn
13.6
12.5
12.0
11.5
11.4
11.4
ns
tpd is the same as tPLH and tPHL; tdis is the same as tPLZ and tPHZ; ten is the same as tPZL and tPZH.
Table 10. Typical power dissipation capacitance at VCC(A) = VCC(B) and Tamb = 25 C[1][2]
Voltages are referenced to GND (ground = 0 V).
Symbol Parameter
CPD
[1]
power dissipation
capacitance
Conditions
VCC(A) and VCC(B)
Unit
1.8 V
2.5 V
3.3 V
5.0 V
A port: (direction A to B);
B port: (direction B to A)
1
1
1
2
pF
A port: (direction B to A);
B port: (direction A to B)
13
13
13
13
pF
CPD is used to determine the dynamic power dissipation (PD in W).
PD = CPD VCC2 fi N + (CL VCC2 fo) where:
fi = input frequency in MHz;
fo = output frequency in MHz;
CL = load capacitance in pF;
VCC = supply voltage in V;
N = number of inputs switching;
(CL VCC2 fo) = sum of the outputs.
[2]
fi = 10 MHz; VI = GND to VCC; tr = tf = 1 ns; CL = 0 pF; RL = .
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
10 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
Table 11. Dynamic characteristics for temperature range 40 C to +85 C[1]
Voltages are referenced to GND (ground = 0 V); for test circuit see Figure 7; for wave forms see Figure 5 and Figure 6.
Symbol Parameter
Conditions
VCC(B)
Unit
1.5 V 0.1 V 1.8 V 0.15 V 2.5 V 0.2 V 3.3 V 0.3 V 5.0 V 0.5 V
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
13
ns
VCC(A) = 1.5 V 0.1 V
tpd
propagation
delay
An to Bn
1.7
27
1.7
23
1.3
18
1.0
15
0.8
Bn to An
0.9
27
0.9
25
0.8
23
0.7
23
0.7
22
ns
tdis
disable time
OE to An
1.5
30
1.5
30
1.5
30
1.5
30
1.4
30
ns
OE to Bn
2.4
34
2.4
33
1.9
15
1.7
14
1.3
12
ns
OE to An
0.4
34
0.4
34
0.4
34
0.4
34
0.4
34
ns
OE to Bn
1.8
36
1.8
34
1.5
18
1.2
15
0.9
13
ns
An to Bn
1.7
25
1.7
21.9
1.3
9.2
1.0
7.4
0.8
7.1
ns
Bn to An
0.9
23
0.9
23.8
0.8
23.6
0.7
23.4
0.7
23.4 ns
ten
enable time
VCC(A) = 1.8 V 0.15 V
tpd
propagation
delay
OE to An
1.5
30
1.5
29.6
1.5
29.4
1.5
29.3
1.4
29.2 ns
OE to Bn
2.4
33
2.4
32.2
1.9
13.1
1.7
12.0
1.3
10.3 ns
OE to An
0.4
24
0.4
24.0
0.4
23.8
0.4
23.7
0.4
23.7 ns
OE to Bn
1.8
34
1.8
32.0
1.5
16.0
1.2
12.6
0.9
10.8 ns
propagation
delay
An to Bn
1.5
23
1.5
21.4
1.2
9.0
0.8
6.2
0.6
4.8
ns
Bn to An
1.2
18
1.2
9.3
1.0
9.1
1.0
8.9
0.9
8.8
ns
tdis
disable time
OE to An
1.4
9.0
1.4
9.0
1.4
9.0
1.4
9.0
1.4
9.0
ns
ns
ten
enable time
tdis
ten
disable time
enable time
VCC(A) = 2.5 V 0.2 V
tpd
OE to Bn
2.3
31
2.3
29.6
1.8
11.0
1.7
9.3
0.9
6.9
OE to An
1.0
10.9
1.0
10.9
1.0
10.9
1.0
10.9
1.0
10.9 ns
OE to Bn
1.7
32
1.7
28.2
1.5
12.9
1.2
9.4
1.0
6.9
ns
VCC(A) = 3.3 V 0.3 V
tpd
tdis
ten
propagation
delay
An to Bn
1.5
23
1.5
21.2
1.1
8.8
0.8
6.3
0.5
4.4
ns
Bn to An
0.8
15
0.8
7.2
0.8
6.2
0.7
6.1
0.6
6.0
ns
disable time
OE to An
1.6
8.2
1.6
8.2
1.6
8.2
1.6
8.2
1.6
8.2
ns
OE to Bn
2.1
30
2.1
29.0
1.7
10.3
1.5
8.6
0.8
6.3
ns
enable time
OE to An
0.8
8.1
0.8
8.1
0.8
8.1
0.8
8.1
0.8
8.1
ns
OE to Bn
1.8
31
1.8
27.7
1.4
12.4
1.1
8.5
0.9
6.4
ns
22
1.5
21.4
1.0
8.8
0.7
6.0
0.4
4.2
ns
VCC(A) = 5.0 V 0.5 V
tpd
propagation
delay
An to Bn
1.5
Bn to An
0.7
13
0.7
7.0
0.4
4.8
0.3
4.5
0.3
4.3
ns
tdis
disable time
OE to An
0.3
5.4
0.3
5.4
0.3
5.4
0.3
5.4
0.3
5.4
ns
OE to Bn
2.0
30
2.0
28.7
1.6
9.7
1.4
8.0
0.7
5.7
ns
OE to An
0.7
6.4
0.7
6.4
0.7
6.4
0.7
6.4
0.7
6.4
ns
OE to Bn
1.5
31
1.5
27.6
1.3
11.4
1.0
8.1
0.9
6.0
ns
ten
[1]
enable time
tpd is the same as tPLH and tPHL; tdis is the same as tPLZ and tPHZ; ten is the same as tPZL and tPZH.
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
11 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
Table 12. Dynamic characteristics for temperature range 40 C to +125 C[1]
Voltages are referenced to GND (ground = 0 V); for test circuit see Figure 7; for wave forms see Figure 5 and Figure 6.
Symbol Parameter
Conditions
VCC(B)
Unit
1.5 V 0.1 V 1.8 V 0.15 V 2.5 V 0.2 V 3.3 V 0.3 V 5.0 V 0.5 V
Min
Max
Min
Max
Min
Max
Min
Max
Min
Max
16
ns
VCC(A) = 1.5 V 0.1 V
tpd
propagation
delay
An to Bn
1.7
32
1.7
27
1.3
21
1.0
18
0.8
Bn to An
0.9
32
0.9
30
0.8
28
0.7
28
0.7
26
ns
tdis
disable time
OE to An
1.5
34
1.5
34
1.5
34
1.5
34
1.4
34
ns
OE to Bn
2.4
41
2.4
40
1.9
18
1.7
17
1.3
15
ns
OE to An
0.4
40
0.4
40
0.4
40
0.4
40
0.4
40
ns
OE to Bn
1.8
43
1.8
41
1.5
22
1.2
18
0.9
16
ns
An to Bn
1.7
30
1.7
25.9
1.3
13.2
1.0
11.4
0.8
11.1
ns
Bn to An
0.9
27
0.9
28.8
0.8
27.6
0.7
27.4
0.7
27.4 ns
ten
enable time
VCC(A) = 1.8 V 0.15 V
tpd
propagation
delay
OE to An
1.5
34
1.5
33.6
1.5
33.4
1.5
33.3
1.4
33.2 ns
OE to Bn
2.4
40
2.4
36.2
1.9
17.1
1.7
16.0
1.3
14.3 ns
OE to An
0.4
28
0.4
28
0.4
27.8
0.4
27.7
0.4
27.7 ns
OE to Bn
1.8
41
1.8
40
1.5
20
1.2
16.6
0.9
14.8 ns
propagation
delay
An to Bn
1.5
28
1.5
25.4
1.2
13
0.8
10.2
0.6
8.8
Bn to An
1.2
23
1.2
13.3
1.0
13.1
1.0
12.9
0.9
12.8 ns
tdis
disable time
OE to An
1.4
13
1.4
13
1.4
13
1.4
13
1.4
ten
enable time
tdis
ten
disable time
enable time
VCC(A) = 2.5 V 0.2 V
tpd
13
ns
ns
OE to Bn
2.3
37
2.3
33.6
1.8
15
1.7
14.3
0.9
10.9 ns
OE to An
1.0
17.2
1.0
17.2
1.0
17.3
1.0
17.2
1.0
17.3 ns
OE to Bn
1.7
38
1.7
32.2
1.5
18.1
1.2
14.1
1.0
11.2
propagation
delay
An to Bn
1.5
28
1.5
25.2
1.1
12.8
0.8
10.3
0.5
10.4 ns
Bn to An
0.8
18
0.8
11.2
0.8
10.2
0.7
10.1
0.6
disable time
OE to An
1.6
12.2
1.6
12.2
1.6
12.2
1.6
12.2
1.6
12.2 ns
OE to Bn
2.1
36
2.1
33
1.7
14.3
1.5
12.6
0.8
10.3 ns
ns
VCC(A) = 3.3 V 0.3 V
tpd
tdis
ten
enable time
10
ns
OE to An
0.8
14.1
0.8
14.1
0.8
13.6
0.8
13.2
0.8
13.6 ns
OE to Bn
1.8
37
1.8
31.7
1.4
18.4
1.1
12.9
0.9
10.9 ns
1.5
26
1.5
25.4
1.0
12.8
0.7
10
0.4
8.2
ns
VCC(A) = 5.0 V 0.5 V
tpd
propagation
delay
An to Bn
Bn to An
0.7
16
0.7
11
0.4
8.8
0.3
8.5
0.3
8.3
ns
tdis
disable time
OE to An
0.3
9.4
0.3
9.4
0.3
9.4
0.3
9.4
0.3
9.4
ns
OE to Bn
2.0
36
2.0
32.7
1.6
13.7
1.4
12
0.7
9.7
ns
OE to An
0.7
10.9
0.7
10.9
0.7
10.9
0.7
10.9
0.7
10.9 ns
OE to Bn
1.5
37
1.5
31.6
1.3
18.4
1.0
13.7
0.9
10.7 ns
ten
[1]
enable time
tpd is the same as tPLH and tPHL; tdis is the same as tPLZ and tPHZ; ten is the same as tPZL and tPZH.
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
12 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
11. Waveforms
VI
VM
An, Bn input
GND
tPHL
tPLH
VOH
VM
Bn, An output
VOL
001aai475
Measurement points are given in Table 13.
VOL and VOH are typical output voltage levels that occur with the output load.
Fig 5.
The data input (An, Bn) to output (Bn, An) propagation delay times
VI
OE input
VM
GND
tPLZ
tPZL
VCCO
output
LOW-to-OFF
OFF-to-LOW
VM
VX
VOL
tPZH
tPHZ
VOH
VY
output
HIGH-to-OFF
OFF-to-HIGH
VM
GND
outputs
enabled
outputs
enabled
outputs
disabled
001aai474
Measurement points are given in Table 13.
VOL and VOH are typical output voltage levels that occur with the output load.
Fig 6.
Enable and disable times
Table 13.
Measurement points
Supply voltage
Input[1]
Output[2]
VCC(A), VCC(B)
VM
VM
VX
VY
1.2 V to 1.6 V
0.5VCCI
0.5VCCO
VOL + 0.1 V
VOH 0.1 V
1.65 V to 2.7 V
0.5VCCI
0.5VCCO
VOL + 0.15 V
VOH 0.15 V
3.0 V to 5.5 V
0.5VCCI
0.5VCCO
VOL + 0.3 V
VOH 0.3 V
[1]
VCCI is the supply voltage associated with the data input port.
[2]
VCCO is the supply voltage associated with the output port.
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
13 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
tW
VI
90 %
negative
pulse
VM
VM
10 %
0V
tf
tr
tr
tf
VI
90 %
positive
pulse
VM
VM
10 %
0V
tW
VEXT
VCC
VI
RL
VO
G
DUT
RT
RL
CL
001aae331
Test data is given in Table 14.
RL = Load resistance.
CL = Load capacitance including jig and probe capacitance.
RT = Termination resistance.
VEXT = External voltage for measuring switching times.
Fig 7.
Load circuitry for switching times
Table 14.
Test data
Supply voltage
Input
VCC(A), VCC(B)
VI[1]
t/V[2]
Load
CL
RL
tPLH, tPHL
tPZH, tPHZ
tPZL, tPLZ[3]
1.2 V to 5.5 V
VCCI
1.0 ns/V
15 pF
2 k
open
GND
2VCCO
[1]
VCCI is the supply voltage associated with the data input port.
[2]
dV/dt 1.0 V/ns.
[3]
VCCO is the supply voltage associated with the output port.
74LVC_LVCH8T245
Product data sheet
VEXT
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
14 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
12. Typical propagation delay characteristics
001aal268
14
tPHL
(ns)
12
(1)
10
001aal269
14
tPLH
(ns)
12
(1)
10
(2)
(3)
(4)
(5)
(6)
8
6
(2)
(3)
8
(4)
(5)
(6)
6
4
4
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
a. HIGH to LOW propagation delay (A to B)
001aal270
14
tPHL
(ns)
12
(1)
(2)
(3)
(4)
(5)
(6)
10
0
10
15
20
25
30
CL (pF)
35
b. LOW to HIGH propagation delay (A to B)
001aal271
14
tPLH
(ns)
12
(1)
(2)
(3)
(4)
(5)
(6)
10
8
8
6
6
4
4
2
2
0
5
0
0
5
10
15
20
25
30
CL (pF)
35
c. HIGH to LOW propagation delay (B to A)
0
5
10
15
20
25
30
CL (pF)
35
d. LOW to HIGH propagation delay (B to A)
(1) VCC(B) = 1.2 V.
(2) VCC(B) = 1.5 V.
(3) VCC(B) = 1.8 V.
(4) VCC(B) = 2.5 V.
(5) VCC(B) = 3.3 V.
(6) VCC(B) = 5.0 V.
Fig 8.
Typical propagation delay versus load capacitance; Tamb = 25 C; VCC(A) = 1.2 V
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
15 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
001aal272
14
tPHL
(ns)
12
001aal273
14
tPLH
(ns)
12
(1)
(1)
10
10
(2)
(2)
8
8
(3)
(4)
(5)
(6)
6
(3)
(4)
(5)
(6)
6
4
4
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
a. HIGH to LOW propagation delay (A to B)
001aal274
14
tPHL
(ns)
12
10
6
5
10
15
20
25
30
CL (pF)
35
b. LOW to HIGH propagation delay (A to B)
001aal275
14
tPLH
(ns)
12
10
(1)
(2)
(3)
(4)
(5)
(6)
8
0
(1)
(2)
(3)
(4)
(5)
(6)
8
6
4
4
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
c. HIGH to LOW propagation delay (B to A)
0
5
10
15
20
25
30
CL (pF)
35
d. LOW to HIGH propagation delay (B to A)
(1) VCC(B) = 1.2 V.
(2) VCC(B) = 1.5 V.
(3) VCC(B) = 1.8 V.
(4) VCC(B) = 2.5 V.
(5) VCC(B) = 3.3 V.
(6) VCC(B) = 5.0 V.
Fig 9.
Typical propagation delay versus load capacitance; Tamb = 25 C; VCC(A) = 1.5 V
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
16 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
001aal276
14
tPHL
(ns)
12
001aal277
14
tPLH
(ns)
12
(1)
(1)
10
10
8
(2)
8
(2)
(3)
(3)
6
6
(4)
(5)
(6)
4
4
2
2
0
(4)
(5)
(6)
0
0
5
10
15
20
25
30
CL (pF)
35
a. HIGH to LOW propagation delay (A to B)
001aal278
14
tPHL
(ns)
12
10
0
5
10
15
20
25
8
6
35
b. LOW to HIGH propagation delay (A to B)
001aal279
14
tPLH
(ns)
12
10
(1)
(2)
(3)
(4)
(5)
(6)
30
CL (pF)
(1)
(2)
(3)
(4)
(5)
(6)
8
6
4
4
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
c. HIGH to LOW propagation delay (B to A)
0
5
10
15
20
25
30
CL (pF)
35
d. LOW to HIGH propagation delay (B to A)
(1) VCC(B) = 1.2 V.
(2) VCC(B) = 1.5 V.
(3) VCC(B) = 1.8 V.
(4) VCC(B) = 2.5 V.
(5) VCC(B) = 3.3 V.
(6) VCC(B) = 5.0 V.
Fig 10. Typical propagation delay versus load capacitance; Tamb = 25 C; VCC(A) = 1.8 V
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
17 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
001aal280
14
tPHL
(ns)
12
(1)
(1)
10
001aal281
14
tPLH
(ns)
12
10
8
8
(2)
(2)
6
(3)
6
4
(4)
(5)
(6)
4
2
(3)
(4)
(5)
(6)
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
a. HIGH to LOW propagation delay (A to B)
001aal282
14
tPHL
(ns)
12
10
0
5
10
15
20
25
30
CL (pF)
35
b. LOW to HIGH propagation delay (A to B)
001aal283
14
tPLH
(ns)
12
10
8
8
(1)
(2)
(3)
(4)
(5)
(6)
6
4
(1)
(2)
(3)
(4)
(5)
(6)
6
4
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
c. HIGH to LOW propagation delay (B to A)
0
5
10
15
20
25
30
CL (pF)
35
d. LOW to HIGH propagation delay (B to A)
(1) VCC(B) = 1.2 V.
(2) VCC(B) = 1.5 V.
(3) VCC(B) = 1.8 V.
(4) VCC(B) = 2.5 V.
(5) VCC(B) = 3.3 V.
(6) VCC(B) = 5.0 V.
Fig 11. Typical propagation delay versus load capacitance; Tamb = 25 C; VCC(A) = 2.5 V
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
18 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
001aal284
14
tPHL
(ns)
12
(1)
10
001aal285
14
tPLH
(ns)
12
(1)
10
8
8
(2)
(2)
6
(3)
6
(3)
4
(4)
(5)
(6)
4
(4)
(5)
(6)
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
a. HIGH to LOW propagation delay (A to B)
001aal286
14
tPHL
(ns)
12
10
0
5
10
15
20
25
30
CL (pF)
35
b. LOW to HIGH propagation delay (A to B)
001aal287
14
tPLH
(ns)
12
10
8
8
(1)
(2)
(3)
(4)
(5)
(6)
6
4
(1)
(2)
(3)
(4)
(5)
(6)
6
4
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
c. HIGH to LOW propagation delay (B to A)
0
5
10
15
20
25
30
CL (pF)
35
d. LOW to HIGH propagation delay (B to A)
(1) VCC(B) = 1.2 V.
(2) VCC(B) = 1.5 V.
(3) VCC(B) = 1.8 V.
(4) VCC(B) = 2.5 V.
(5) VCC(B) = 3.3 V.
(6) VCC(B) = 5.0 V.
Fig 12. Typical propagation delay versus load capacitance; Tamb = 25 C; VCC(A) = 3.3 V
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
19 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
001aal288
14
tPHL
(ns)
12
(1)
10
001aal289
14
tPLH
(ns)
12
(1)
10
8
8
(2)
(2)
6
(3)
6
(3)
4
(4)
(5)
(6)
4
(4)
(5)
(6)
2
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
a. HIGH to LOW propagation delay (A to B)
001aal290
14
tPHL
(ns)
12
0
8
8
4
15
20
25
35
(1)
(2)
(3)
(4)
(5)
(6)
6
4
2
30
CL (pF)
001aal291
14
tPLH
(ns)
12
10
(1)
(2)
(3)
(4)
(5)
(6)
10
b. LOW to HIGH propagation delay (A to B)
10
6
5
2
0
0
0
5
10
15
20
25
30
CL (pF)
35
c. HIGH to LOW propagation delay (B to A)
0
5
10
15
20
25
30
CL (pF)
35
d. LOW to HIGH propagation delay (B to A)
(1) VCC(B) = 1.2 V.
(2) VCC(B) = 1.5 V.
(3) VCC(B) = 1.8 V.
(4) VCC(B) = 2.5 V.
(5) VCC(B) = 3.3 V.
(6) VCC(B) = 5.0 V.
Fig 13. Typical propagation delay versus load capacitance; Tamb = 25 C; VCC(A) = 5 V
74LVC_LVCH8T245
Product data sheet
All information provided in this document is subject to legal disclaimers.
Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
20 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
13. Application information
13.1 Unidirectional logic level-shifting application
The circuit given in Figure 14 is an example of the 74LVC8T245; 74LVCH8T245 being
used in an unidirectional logic level-shifting application.
VCC1
VCC1
VCC(A)
GND
An
VCC(B)
74LVC8T245
74LVCH8T245
DIR
VCC2
VCC2
Bn
OE
system-1
system-2
001aak438
Schematic given for one channel.
Fig 14. Unidirectional logic level-shifting application
Table 15.
74LVC_LVCH8T245
Product data sheet
Description unidirectional logic level-shifting application
Name
Function
Description
VCC(A)
VCC1
supply voltage of system-1 (1.2 V to 5.5 V)
GND
GND
device GND
A
OUT
output level depends on VCC1 voltage
B
IN
input threshold value depends on VCC2 voltage
DIR
DIR
the GND (LOW level) determines B port to A port direction
VCC(B)
VCC2
supply voltage of system-2 (1.2 V to 5.5 V)
OE
OE
The GND (LOW level) enables the output ports
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Rev. 3 — 12 December 2011
©
Nexperia B.V. 2017. All rights reserved
21 of 28
74LVC8T245; 74LVCH8T245
Nexperia
8-bit dual supply translating transceiver; 3-state
13.2 Bidirectional logic level-shifting application
Figure 15 shows the 74LVC8T245; 74LVCH8T245 being used in a bidirectional logic
level-shifting application.
VCC1
VCC1
VCC2
VCC2
VCC(B)
VCC(A)
I/O-1
I/O-2
PULL-UP/DOWN
GND
A
74LVC8T245
74LVCH8T245
DIR
PULL-UP/DOWN
B
OE
OE
DIR CTRL
system-1
system-2
001aak439
Schematic given for one channel.
Pull-up or pull-down only needed for 74LVC8T245.
Fig 15. Bidirectional logic level-shifting application
Table 16 gives a sequence that will illustrate data transmission from system-1 to system-2
and then from system-2 to system-1.
Table 16.
Description bidirectional logic level-shifting application[1]
State DIR CTRL OE
I/O-1
I/O-2
Description
1
H
L
output
input
system-1 data to system-2
2
H
H
Z
Z
system-2 is getting ready to send data to
system-1. I/O-1 and I/O-2 are disabled. The
bus-line state depends on bus hold.
3
L
H
Z
Z
DIR bit is set LOW. I/O-1 and I/O-2 still are
disabled. The bus-line state depends on bus
hold.
4
L
L
input
output
system-2 data to system-1
[1]
H = HIGH voltage level; L = LOW voltage level; Z = high-impedance OFF-state.
13.3 Power-up considerations
The device is designed such that no special power-up sequence is required other than
GND being applied first.
Table 17.
VCC(A)
74LVC_LVCH8T245
Product data sheet
Typical total supply current (ICC(A) + ICC(B))
VCC(B)
Unit
0V
1.8 V
2.5 V
3.3 V
5.0 V
0V
0