IMP38C/HC/42/3/4/5
Electrical Characteristics
Unless otherwise noted, V
CC
= 15V, R
T
= 10kΩ and C
T
= 3.3nF. Specifications are over the – 40°C to +85°C ambient temperature range.
Bold/blue
specifications indicate enhanced performance features.
Parameter
Current Sense
Gain
Over Current Protection Threshold
Power Supply Rejection Ratio
Input Bias Current
Delay to Output
Output
IMP38C4x
ON Resistance, High
ON Resistance, Low
IMP38HC4x
ON Resistance, High
ON Resistance, Low
Peak Drive Current
IMP38C4x Rise Time
IMP38C4x Fall Time
IMP38HC4x Rise Time
IMP38HC4x Fall Time
Shoot-through Current
Undervoltage Lockout
Start Threshold
Minimum Operating Voltage
Pulse Width Modulator
Maximum Duty Cycle
Maximum Duty Cycle
Minimum Duty Cycle
Supply Current
Start-Up Current
Operating Current
Symbol
A
VOL
PSRR
I
B
T
PD
Conditions
Notes 1, 2 and 3
Vcomp = max, Note 2
V
START
≤
V
CC
≤
18V
V
FB
= 0V, ISNS 0V to 2V, C
L
= 1nF
Min
2.90
0.9
Typ
3.00
0.98
70
– 0.1
50
Max
3.10
1.1
– 2.0
65
Units
V/V
V
dB
µA
ns
R
DS (ON)
I
SOURCE
= 0.2A
I
SINK
= 0.2A
I
SOURCE
= 0.2A
I
SINK
= 0.2A
HC devices
H devices
T
A
= 25°C, C
L
= 1nF
T
A
= 25°C, C
L
= 1nF
T
A
= 25°C, C
L
= 1nF
T
A
= 25°C, C
L
= 1nF
20
11
10
5.5
1.0
0.5
40
30
20
15
0
13.5
7.8
8
7.0
94
48
14.5
8.4
9
7.6
96
50
0
70
50
50
40
Ω
R
DS (ON)
Ω
A
ns
ns
ns
ns
mA
V
V
T
R
T
F
T
R
T
F
IMP38C42/4, IMP38HC42/4
IMP38C43/5, IMP38HC43/5
IMP38C42/4, IMP38HC42/4
IMP38C43/5, IMP38HC43/5
IMP38C42/3, IMP38HC42/3,
IMP38C44/5, IMP38HC44/5
15.5
9.0
10
8.2
%
%
%
µA
mA
I
CC
V
CC
= 13V for IMP38C42/44, IMP38HC42/44
V
CC
= 7.5V for IMP38C43/45, IMP38HC43/45
V
FB
= V
IS
= 0
95
0.5
120
1.5
Note 1. Guaranteed by design. Not 100% tested in production.
Note 2. Measured at trip point of V
FB
= 0V.
Note 3. Gain is defined as:
A
=
∆
V
COMP
, 0
≤
V
CS
≤
0.8V
∆
V
CS
Note 4. Adjust V
CC
above the start threshold before setting at 15V.
Note 5. Output frequency equals the oscillator frequency for
IMP38C42/3 and IMP38HC42/3 devices. Output frequency
equals one-half the oscillator frequency for IMP38C44/5 and
IMP38HC44/5 devices.
Table 1. Startup and Operating Voltage Selection Guide
UVLO Thresholds
Duty Cycle
0% to 96%
0% to 50%
Start-up at 8.4V
Operating Minimum = 7.6V
IMP38C43/HC43
IMP38C45/HC45
Start-up at 14.5V
Operating Minimum = 9.0V
IMP38C42/HC42
IMP38C44/HC44
38C/HC_t03.eps
© 2000 IMP, Inc.
PWM Controllers
5
IMP [ IMP, INC ]
