TCF6000 Datasheet, PDF (2/6 Pages) Motorola, Inc – PERIPHERAL CLAMPING ARRAY

TCF6000
MAXIMUM RATINGS (TA = 25°C, unless otherwise noted, Note 1.)
Rating
Symbol
Value
Supply Voltage
Supply Current
Clamping Current
Junction Temperature
Power Dissipation (TA = + 85°C)
Thermal Resistance (Junction–Ambient)
Operating Ambient Temperature Range
Storage Temperature Range
VCC
Ii
IIK
TJ
PD
θ_JA
TA
Tstg
6.0
300
±50
150
400
100
–40 to +85
–55 to + 150
NOTE: 1. Values beyond which damage may occur.
Unit
V
mA
mA
°C
m/W
°C/W
°C
°C
ELECTRICAL CHARACTERISTICS (TA = 25°C, 4.5 ≤ VCC ≤ 5.5 V, unless otherwise noted.)
Characteristics
Symbol
Positive Clamping Voltage (Note 2)
(IIK = 10 mA, –40°C ≤ TA ≤ + 85°C)
V(IK)
Positive Peak Clamping Current
Negative Peak Clamping Voltage
(IIK = –10 mA, –40°C ≤ TA ≤ + 85°C)
IIK(P)
V(IK)
Negative Peak Clamping Current
Output Leakage Current
(0 V ≤ Vin ≤ VCC)
(0 V ≤ Vin ≤ VCC, –40°C ≤ TA ≤ + 85°C)
IIK(P)
IL
ILT
Channel Crosstalk (ACT = 20 log IL/IIK)
Quiescent Current (Package)
ACT
IB
NOTE: 2. The device might not give 100% protection in CMOS applications.
Min
–
–
–0.3
–20
–
–
100
–
Max
Unit
VCC + 1.0
V
20
mA
–
V
–
mA
µA
1.0
5.0
–
dB
2.0
mA
CIRCUIT DESCRIPTION
To ensure the reliable operation of any integrated circuit
based electronics system, care has been taken that voltage
transients do not reach the device I/O pins. Most NMOS,
HMOS and Bipolar integrated circuits are particularly
sensitive to negative voltage peaks which can provoke
latch–up or otherwise disturb the normal functioning of the
circuit, and in extreme cases may destroy the device.
Generally the maximum rating for a negative voltage
transients on integral circuits is –0.3 V over the whole
temperature range. Classical protection units have consisted
of diode/resistor networks as shown in Figures 2a and 2b.
The arrangement in Figure 2a does not, in general, meet
the specification and is therefore inadequate.
The problem with the solution shown if Figure 2b lies
mainly with the high current drain through the biassing
devices R1 and D3. A second problem exists if the input line
carries an analog signal. When Vin is close to the ground
potential, currents arising from leakage and mismatch
between D3 and D2 can be sourced into the input line, thus
disturbing the reading.
Figure 2. Classical Protection Circuits
(a)
VCC
(b)
VCC
Vin Rin
Cin
D1
µC
D2
R1
Vin Rin
D1 _µC
D2
Cin
D3
Gnd
Gnd
Figure 3 shows the clamping characteristics which
are common to each of the six cells in the Peripheral
Clamping Array.
As with the classical protection circuits, positive voltage
transients are clamped by means of a fast diode to the V_CC
supply line.
2
MOTOROLA ANALOG IC DEVICE DATA