NTE NTE7098 Integrated circuit current mode pulse width modulator (pwm) control circuit Datasheet

NTE7098 & NTE7099
Integrated Circuit
Current Mode Pulse Width Modulator (PWM)
Control Circuit
Description:
The NTE7098 and NTE7099 are integrated circuits in 8–Lead DIP type packages that incorporate a
new precision temperature–controlled oscillator to minimize variations in frequency. An internal
toggle flip–flop, which blanks the output off every other clock cycle, limits the duty–cycle range to less
than 50%. An under–voltage lockout ensures that VREF is stabilized before the output stage is enabled.
Other features include low start–up current, pulse–by–current limiting, and high–current totem pole
output for driving capacitive loads, such as the gate of a power MOSFET. The output is low in the
off state, consistent with N–channel devices.
Features:
D Optimized for Off–Line Control
D Temperature Compensated Oscillator
D 50% Maximum Duty–Cycle Clamp
D Vref Stabilized before Output Stage is Enabled
D Low Start–Up Current
D Pulse–by Pulse Current Limiting
D Improved U/V Lockout
D Double Pulse Suppression
D 1% Trimmed Bandgap Reference
D High Current Totem Pole Output
Absolute Maximum Ratings:
Supply Voltage (ICC < 30mA) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Self Limiting
Supply Voltage (Low Impedence Source) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30V
Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±1A
Output Energy (Capacitive Load) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5µJ
Analog Inputs (VFB, VSENSE) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3V to VCC
Error Amp Output Sink Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mA
Elecrtrical Characteristics: (0° ≤ TA ≤ +70°C, VCC = 15V, RT = 10K, CT = 3.3nF for sawtooth
mode, Note 1 unless otherwise specified)
Parameter
Test Conditions
Min
Typ
Max
Unit
4.9
5.0
5.1
V
Reference Section
Output Voltage
TJ = +25°C, IREF = 1mA
Line Regulation
12V ≤ VIN ≤ 25V
–
6
20
mV
Load Regulation
1mA ≤ IREF ≤ 20mA
–
6
25
mV
Temperature Stability
Note 2
Total Output Variation
Line, Load, Temperature, Note 2
Output Noise Voltage
10Hz ≤ f ≤ 10kHz, TJ = +25°C, Note 2
Long Term Stability
TA = +125°C, 1000Hrs., Note 2
–
Output Short Circuit
TA = +25°C
–30
Initial Accuracy
Sawtooth Mode, TJ = +25°C
47
Voltage Stability
12V ≤ VCC ≤ 25V
–
Temperature Stability
Sawtooth Mode, 0° ≤ TA ≤ +70°C, Note 2
Amplitude
VPIN4 peak to peak
–
0.2
0.4
mV/°C
4.82
–
5.18
V
–
50
–
µV
5
25
mV
–100
–180
mA
52
57
kHz
0.2
1.0
%
–
5
–
%
–
1.7
–
V
2.42
2.50
2.58
V
–
–0.3
–2.0
µA
Oscillator Section
Error Amp Section
Input Voltage
VCOMP = 2.5V
Input Bias Current
VFB = 0V
AVOL
2V ≤ VO ≤ 4V
65
90
–
dB
Unity Gain Bandwidth
Note 2
0.7
1.0
–
MHz
PSRR
12V ≤ VCC ≤ 25V
60
70
–
dB
Output Sink Current
VFB = 2.7V, VCOMP = 1.1V
2
6
–
mA
Output Source Current
VFB = 2.3V, VCOMP = 5V
–0.5
–0.8
–
mA
VOUT High
VFB = 2.3V, RL = 15K to GND
5
6
–
V
VOUT Low
VFB = 2.7V, RL = 15K to Pin8
–
0.7
1.1
V
Current Sense Section
Gain
Note 3, Note 4
2.85
3.00
3.15
V/V
Maximum Input Signal
VCOMP = 5V, Note 3
0.9
1.0
1.1
V
PSRR
12V ≤ VCC ≤ 25V, Note 3
–
70
–
dB
Input Bias Current
VSENSE = 0V
–
–2
–10
µA
Delay to Output
TJ = +25°C, Note 2
–
150
300
ns
ISINK = 20mA
–
0.1
0.4
V
Output Section
Output Low Level
ISINK = 200mA
Output High Level
–
1.5
2.2
V
ISOURCE = 20mA
13.0
13.5
–
V
ISOURCE = 200mA
12.0
13.5
–
V
Rise Time
TJ = +25°C,CL = 1nF, Note 2
–
50
150
ns
Fall Time
TJ = +25°C,CL = 1nF, Note 2
–
50
150
ns
–
0.5
1.0
mA
Total Standby Current
Start–Up Current
Operating Supply Current
VFB = VSENSE = 0V, RT = 10K, CT = 3.3nF
–
11
17
mA
VCC Zener Voltage
ICC = 25mA
–
34
–
V
Maximum Duty Cycle
46
48
50
%
Minimum Duty Cycle
–
–
0
%
PWM Section
Parameter
Test Conditions
Min
Typ
Max
Unit
14.5
16.0
17.5
V
7.8
8.4
9.0
V
8.5
10.0
11.5
V
7.0
7.6
8.2
V
Under–Voltage Lockout Section
Start Threshold
NTE7098
NTE7099
Minimum Operating Voltage
NTE7098
After Turn On
NTE7099
Note
Note
Note
Note
1.
2.
3.
4.
Adjust VCC above the start threshold before setting at 15V.
These parameters, although guaranteed, are not 100% tested in production.
Parameter measured at trip point of latch with VFB = 0.
Gain defined as:
∆VCOMP
; 0 ≤ VPIN3 ≤ 0.8V
A=
∆VSENSE
Pin Connection Diagram
COMP
1
8
VREF
VFB
2
7
VCC
ISENSE
3
6
OUTPUT
RTCT
4
5
GND
8
5
.260 (6.6)
1
4
.390 (9.9)
Max
.300 (7.62)
.155
(3.93)
.100 (2.54)
.145 (3.68)
.300 (7.62)
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