ICL7667CBAZA-T Intersil, ICL7667CBAZA-T Datasheet - Page 6

• Manufacturer Part Number: ICL7667CBAZA-T
• Description: IC MOSFET DRIVER DUAL 8-SOIC
• Manufacturer: Intersil

Specifications of ICL7667CBAZA-T

• Configuration: Low-Side
• Input Type: Inverting
• Delay Time: 20ns
• Current - Peak: 1A
• Number Of Configurations: 2
• Number Of Outputs: 2
• Voltage - Supply: 4.5 V ~ 15 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• High Side Voltage - Max (bootstrap): -
• Other names: ICL7667CBAZA-TTR

overcome this high capacitance and quickly turns the
MOSFET fully on or off.
Direct Drive of MOSFETs
Figure 11 shows interfaces between the ICL7667 and typical
switching regulator ICs. Note that unlike the DS0026, the
ICL7667 does not need a dropping resistor and speedup
capacitor between it and the regulator IC. The ICL7667, with
its high slew rate and high voltage drive can directly drive the
gate of the MOSFET. The SG1527 IC is the same as the
FIGURE 9. MOSFET GATE DYNAMIC CHARACTERISTICS
18
16
14
12
10
-2
8
6
4
2
0
0
2
I
212pF
D
= 1A
4
GATE CHARGE - Q
6
680pF
V
DD
8
= 50V
10
6
G
(NANO-COULOMBS)
12
630pF
14
V
SG1527
DD
GND
15V
+V
= 200V
C
16
V
DD
A
B
= 375V
18
20
FIGURE 10A.
ICL7667
ICL7667
V+
V-
SG1525 IC, except that the outputs are inverted. This
inversion is needed since ICL7667 is an inverting buffer.
Transformer Coupled Drive of MOSFETs
Transformers are often used for isolation between the logic
and control section and the power section of a switching
regulator. The high output drive capability of the ICL7667
enables it to directly drive such transformers. Figure 11
shows a typical transformer coupled drive circuit. PWM ICs
with either active high or active low output can be used in
this circuit, since any inversion required can be obtained by
reversing the windings on the secondaries.
Buffered Drivers for Multiple MOSFETs
In very high power applications which use a group of
MOSFETs in parallel, the input capacitance may be very large
and it can be difficult to charge and discharge quickly.
Figure 13 shows a circuit which works very well with very
large capacitance loads. When the input of the driver is zero,
Q
Q
turned off and a current pulse is applied to the gate of Q
the upper half of the ICL7667 through the transformer, T
After about 20ns, T
C
bootstrap circuit may not be needed at frequencies greater
than 10kHz since the input capacitance of Q
slowly.
GS
1
2
is held in conduction by the lower half of the ICL7667 and
is clamped off by Q
and the bootstrap circuit of C
IRF730
+165V
IRF730
1
saturates and Q
DC
1
. When the input goes positive, Q
1
, D
2
1
is held on by its own
and R
2
1
discharges
. This
April 29, 2010
FN2853.6
2
1
.
1
by
is