ML4819CP_NL Fairchild Semiconductor, ML4819CP_NL Datasheet - Page 6

• Manufacturer Part Number: ML4819CP_NL
• Manufacturer: Fairchild Semiconductor

Specifications of ML4819CP_NL

• Start-up Supply Current: 600uA
• Operating Supply Voltage (max): 35V
• Operating Temp Range: 0C to 70C
• Operating Temperature Classification: Commercial
• Package Type: PDIP
• Pin Count: 20
• Mounting: Through Hole
• Lead Free Status / RoHS Status: Compliant

ML4819
ERROR AMPLIFIER
The ML4819 error amplifier is a high open loop gain, wide
bandwidth amplifier.
6
Figure 3. Output Saturation Voltage vs. Output Current
50
30
20
10
–1.0
–2.0
8
5
3
Figure 2. Oscillator Timing Resistance vs. Frequency
3.0
2.0
1.0
20
0
0
V
T
0
CC
A
= 25 C
Figure 4. Error Amplifier Configuration
= 15V
4
3
30
EA OUT
INV
V
CC
+5V
200
50
f
OSC
I
O
, OUTPUT LOAD CURRENT (mA)
, OSCILLATOR FREQUENCY (kHz)
SOURCE SATURATION
+
–
(LOAD TO GROUND)
MAX DUTY CYCLE
SINK SATURATION
T
T
100
(LOAD TO V
A
A
400
= 25 C
= 25 C
0.5mA
CC
+8V
)
200
80 s PULSED LOAD
95%
600
GND
120 Hz RATE
V
CC
300
= 15V
500
800
90%
85%
GAIN MODULATOR
The ML4819 gain modulator is a linear current input
multiplier to provide high immunity to the disturbances
caused by high power switching. The rectified line input
sine wave is converted to a current via a dropping resistor.
In this way, small amounts of ground noise produce an
insignificant effect on the reference to the PWM
comparator.
The output of the gain modulator is a current of the form:
where I
is a current proportional to the output of the error
amplifier. When the error amplifier is saturated high, the
output of the gain modulator is approximately equal to
the I
The gain modulator output current is converted into the
reference voltage for the PWM comparator through a
resistor to ground on the gain modulator output. The gain
modulator output is clamped to 5V to provide current
limiting.
I
SINE
100
–20
I
80
60
40
20
SINE
OUT
0
Figure 5. Error Amplifier Open-Loop Gain and
10
SINE
6
3
Figure 6. Gain Modulator Block Diagram
input current.
is proportional to I
MULTIPLIER
is the current in the dropping resistor, and I
100
I
ERR
Phase vs Frequency
1.0k
GAIN
f, FREQUENCY (Hz)
9V
ERROR
VOLTAGE
10k
SINE
I
SINE
GAIN MODULATOR
100k
I
I
EA
ERR
V
V
R
T
L
A
CC
O
REV. 1.0 10/10/2000
= 25 C
= 100k
= 1.0V TO 5.0V
= 15V
1.0M
PHASE
10M
0
–30
60
90
120
150
180
EA