Datasheet

3-76
Detailed Description
The ICL7667 is a dual high-power CMOS inverter whose
inputs respond to TTL levels while the outputs can swing as
high as 15V. Its high output current enables it to rapidly
charge and discharge the gate capacitance of power
MOSFETs, minimizing the switching losses in switchmode
power supplies. Since the output stage is CMOS, the output
will swing to within millivolts of both ground and V
CC
without
any external parts or extra power supplies as required by the
DS0026/56 family. Although most specifications are at V
CC
=
15V, the propagation delays and specifications are almost
independent of V
CC
.
In addition to power MOS drivers, the ICL7667 is well suited
for other applications such as bus, control signal, and clock
drivers on large memory of microprocessor boards, where
the load capacitance is large and low propagation delays are
required. Other potential applications include peripheral
power drivers and charge-pump voltage inverters.
Input Stage
The input stage is a large N-Channel FET with a P-channel
constant-current source. This circuit has a threshold of about
1.5V, relatively independent of the VCC voltage. This means
that the inputs will be directly compatible with TTL over the
entire 4.5V - 15V V
CC
range. Being CMOS, the inputs draw
less than 1µA of current over the entire input voltage range
of ground to V
CC
. The quiescent current or no load supply
current of the ICL7667 is affected by the input voltage, going
to nearly zero when the inputs are at the 0 logic level and
rising to 7mA maximum when both inputs are at the 1 logic
level. A small amount of hysteresis, about 50mV to 100mV at
the input, is generated by positive feedback around the
second stage.
Output Stage
The ICL7667 output is a high-power CMOS inverter,
swinging between ground and VCC. At V
CC
= 15V, the
output impedance of the inverter is typically 7Ω. The high
FIGURE 5. I
CC
vs FREQUENCY FIGURE 6. NO LOAD I
CC
vs FREQUENCY
FIGURE 7. DELAY AND FALL TIMES vs V
CC
FIGURE 8. RISE TIME vs V
CC
Typical Performance Curves (Continued)
FREQUENCY (Hz)
I
CC
(mA)
V
CC
= 15V
V
CC
= 5V
C
L
= 1nF
100
10
1
100µA
10K 100K 1M 10M
100
10
1
100mA
10k
100k 1M
10M
V
CC
= 15V
V
CC
= 5V
C
L
= 10pF
FREQUENCY (Hz)
I
CC
(mA)
t
f
t
D1
V
CC
(V)
C
L
= 1nF
t
D1
AND t
f
, (ns)
50
40
30
20
10
0
510 15
V
CC
(V)
t
r
= T
D2
C
L
= 10pF
50
40
30
20
10
0
51015
t
r
AND t
D2
, (ns)
ICL7667