Datasheet ML4831CP Datasheet (Micro Linear Corporation)

JULY 2000

ML4831*

Electronic Ballast Controller

GENERAL DESCRIPTION

The ML4831 is a complete solution for a dimmable, high
power factor, high efficiency electronic ballast. Contained
in the ML4831 are controllers for “boost” type power
factor correction as well as for a dimming ballast.

FEATURES

■ Complete Power Factor Correction and Dimming

Ballast Control on one IC

■ Low Distortion, High Efficiency Continuous Boost,

Average Current sensing PFC section

The Power factor circuit uses the average current sensing
method with a gain modulator and over-voltage
protection. This system produces power factors of better
than 0.99 with low input current THD at > 95%
efficiency. Special care has been taken in the design of the
ML4831 to increase system noise immunity by using a
high amplitude oscillator, and a current fed multiplier. An
over-voltage protection comparator inhibits the PFC
section in the event of a lamp out or lamp failure
condition.

The ballast section provides for programmable starting
scenarios with programmable preheat and lamp out-of­socket interrupt times. The IC controls lamp output
through either frequency modulation using lamp current
feedback.

■ Programmable Start Scenario for Rapid or Instant Start

Lamps

■ Lamp Current feedback for Dimming Control

■ Variable Frequency dimming and starting

■ Programmable Restart for lamp out condition to

reduce ballast heating

■ Over-Temperature Shutdown replaces external heat

sensor for safety

■ PFC Over-Voltage comparator eliminates output

“runaway” due to load removal

■ Large oscillator amplitude and gain modulator

improves noise immunity
The ML4831 is designed using Micro Linear‘s Semi­Standard tile array technology. Customized versions of this
IC, optimized to specific ballast architectures can be made
available. Contact Micro Linear or an authorized
representative for more information. * This product is End Of Life as of July 1, 2000

BLOCK DIAGRAM

R(SET)

7

R(T)/C(T)

8

R(X)/C(X)

10

IA OUT

2

IA+

4

I(SINE)

3

EA OUT

1

EA–/OVP

18

OSCILLATOR

PRE-HEAT

AND INTERRUPT

TIMERS

POWER

FACTOR

CONTROLLER

CONTROL

&

GATING LOGIC

UNDER-VOLTAGE

AND THERMAL

SHUTDOWN

OUTPUT
DRIVERS

INTERRUPT

LAMP F.B.

LFB OUT

OUT A

OUT B

PFC OUT

PGND

VCC

V

REF

GND

9

5

6

14

13

15

12

16

17

11

1

ML4831

PIN CONFIGURATION

ML4831

18-Pin DIP (P18)

EA OUT

IA OUT

I(SINE)

IA+

LAMP F.B.

LFB OUT

R(SET)

R(T)/C(T)

INTERRUPT

1

2

3

4

5

6

7

8

9

TOP VIEW

EA–/OVP

18

V

17

REF

VCC

16

PFC OUT

15

OUT A

14

OUT B

13

P GND

12

GND

11

R(X)/C(X)

10

PIN DESCRIPTION

PIN# NAME FUNCTION PIN# NAME FUNCTION

1 EA OUT PFC Error Amplifier output and

compensation node

2 IA OUT Output and compensation node of the

PFC average current transconductance

amplifier.
3 I(SINE) PFC gain modulator input.
4 IA+ Non-inverting input of the PFC

average current transconductance

amplifier and peak current sense point

of the PFC cycle by cycle current limit

comparator.
5 LAMP F.B. Inverting input of an Error Amplifier

used to sense (and regulate) lamp arc

current. Also the input node for

dimming control.
6 LFB OUT Output from the Lamp Current Error

Transconductance Amplifier used for

lamp current loop compensation
7 R(SET) External resistor which sets oscillator

F

, and R(X)/C(X) charging current

MAX

8 R(T)C(T) Oscillator timing components
9 INTERRUPT Input used for lamp-out detection and

restart. A voltage greater than 7.5 volts
resets the chip and causes a restart
after a programmable interval.

10 R(X)/C(X) Sets the timing for the preheat,

dimming lockout, and interrupt
11 GND Ground
12 P GND Power ground for the IC
13 OUT B Ballast MOSFET drive output
14 OUT A Ballast MOSFET drive output
15 PFC OUT Power Factor MOSFET drive output
16 VCC Positive Supply for the IC
17 V

REF

Buffered output for the 7.5V voltage

reference
18 EA–/OVP Inverting input to PFC error amplifier

and OVP comparator input

2

ABSOLUTE MAXIMUM RATINGS

ML4831

Absolute maximum ratings are those values beyond which
the device could be permanently damaged. Absolute
maximum ratings are stress ratings only and functional
device operation is not implied.

Supply Current (ICC) ............................................... 75mA

Output Current, Source or Sink (Pins 13, 14, 15)

DC ................................................................... 250mA

Maximum Forced Current (Pins 1, 2, 6) ................ ±20mA

Maximum Forced Voltage (Pin 2) .................. –0.3V to 6V

Junction Temperature ............................................. 150°C

Storage Temperature Range ..................... –65°C to 150°C

Lead Temperature (Soldering 10 Sec.)..................... 260°C

Thermal Resistance (θ

)

JA

Plastic DIP–P ................................................... 70°C/W

Output Energy (capacitive load per cycle) .............. 1.5 mJ

Gain Modulator I(SINE) Input (Pin 3) ..................... 10 mA

OPERATING CONDITIONS

Analog Inputs (Pins 5, 9, 18) ............... –0.3V to VCC –2V

Pin 4 input voltage ........................................... –3V to 2V

Maximum Forced Voltage (Pins 1, 6) .......... –0.3V to 7.7V

Temperature Range

ML4831C .................................................. 0°C to 85°C

ELECTRICAL CHARACTERISTICS

Unless otherwise specified, R(SET) = 31.6kΩ, R(T) = 16.2kΩ, C(T) = 1.5nF, T
ICC = 25mA

PARAMETER CONDITIONS MIN TYP MAX UNITS

PFC Current Sense Amplifier (Pins 2, 4)

Small Signal Transconductance 130 200 270 µmhos
Input Voltage Range –0.3 3.5 V
Output Low I

Output High I
Source Current I
Sink Current I

PFC Voltage Feedback Amplifier (Pins 1, 18)/Lamp Current Amplifier (Pins 5, 6)

Input Offset Voltage ±3.0 ±10.0 mV
Input Bias Current –0.3 –1.0 µA
Small Signal Transconductance 50 80 110 µmhos
Input Voltage Range –0.3 3.5 V
Output Low V
Output High V
Source Current V
Sink Current V

Gain Modulator

Output Voltage I

Output Voltage Limit I
Offset Voltage I

I(SINE) Input Voltage I

= 0mA, V

SINE

V

= –0.3V, RL = ∞ 0.2 0.4 V

PIN4

= 1.5mA, V

SINE

= 1.5mA, V

SINE

= 0mA, V

SINE

V

= –0.3V, V

PIN4

= 3V, RL = ∞ 0.2 0.4 V

PIN5/18

= 2V, RL = ∞ 7.2 7.5 V

PIN5/18

= 0V, V

PIN5/18

= 5V, V

PIN5/18

= 100µA, V

SINE

I

= 300µA, V

SINE

I

=100µA, V

SINE

I

= 300µA, V

SINE

= 1.5mA, V

SINE

= 0, V

SINE

I

= 150µA, V

SINE

= 200µA 0.8 1.4 1.8 V

SINE

= 0V,

PIN1

= 0V, RL = ∞ 5.2 5.6 6 V

PIN18/4

= 0V, V

PIN18/4

= 0.3V,

PIN2

= 0V 0.3 mA

PIN1

= 7V –0.2 mA

PIN1/6

= 0.3V 0.2 mA

PIN1/6

= 3V 40 mV

PIN1

= 3V 130 mV

PIN1

= 6V 112 mV

PIN1

= 6V 350 mV

PIN1

= 0V 865 mV

PIN18

= 0V 15 mV

PIN18

= 3V 15 mV

PIN18

= Junction Operating Temperature Range,

J

= 5V –0.3 mA

PIN2

3

ML4831

ELECTRICAL CHARACTERISTICS

(Continued)

PARAMETER CONDITIONS MIN TYP MAX UNITS

Oscillator

Initial accuracy TA = 25°C 727680kHz
Voltage stability V

– 3V < VCC <V

CCZ

– 0.5V 1 %

CCZ

Temperature stability 2%
Total Variation Line, temperature 69 83 kHz
Ramp Valley to Peak 2.5 V
C(T) Charging Current (FM Modes) V

C(T) Discharge Current V

= 3V, V

PIN5

V

= 0.9V (Preheat) –78 µA

PIN10

V

= 3V, V

PIN5

V

= Open –156 µA

PIN10

= 2.5V 5 mA

PIN8

PIN8

PIN8

= 2.5V,

= 2.5V,

Output Drive Deadtime 0.75 µs

Reference Section

Output Voltage TA = 25°C, IO = 1mA 7.4 7.5 7.6 V
Line regulation V

– 3V < VCC < V

CCZ

– 0.5V 2 10 mV

CCZ

Load regulation 1mA < IO < 20mA 2 15 mV
Temperature stability 0.4 %
Total Variation Line, load, temp 7.35 7.65 V
Output Noise Voltage 10Hz to 10KHz 50 µV
Long Term Stability TJ = 125°C, 1000 hrs 5 mV
Short Circuit Current VCC < V

– 0.5V, V

CCZ

= 0V –40 mA

REF

Preheat and Interrupt Timer (Pin 10) (R(X) = 590KΩ, C(X) = 5.6µF)

Initial Preheat Period 0.8 s
Subsequent Preheat Period 0.7 s
Start Period 2.1 s
Interrupt Period 6.3 s
Pin 10 Charging Current –19 µA
Pin 10 Open Circuit Voltage VCC = 12.3V in UVLO 0.4 0.9 1.1 V
Pin 10 Maximum Voltage 7.0 7.3 7.7 V
Input Bias Current V

= 1.2V –0.2 µA

PIN10

Preheat Lower Threshold 1.18 V
Preheat Upper Threshold 3.36 V
Interrupt Recovery Threshold 1.18 V
Start Period End Threshold 6.7 V

Interrupt Input (Pin 9)

Interrupt Threshold 7.35 7.5 7.65 V
Input Bias Current –0.3 –1 µA

4

ML4831

ELECTRICAL CHARACTERISTICS

PARAMETER CONDITIONS MIN TYP MAX UNITS

OVP Comparator (Pin 18)

OVP Threshold 2.6 2.7 2.8 V
Hysteresis 0.25 V
Propagation Delay 500 ns

Outputs

Output Voltage Low I

Output Voltage High I

Output Voltage Low in UVLO I
Output Rise/Fall Time CL = 1000pF 50 ns

Under-Voltage Lockout and Bias Circuits

IC Shunt Voltage (V
V

Load Regulation 25mA < ICC < 68mA 150 300 mV

CCZ

V

Total Variation Load, Temp 12.4 14.6 V

CCZ

Start-up Current VCC ≤ 12.3V 1.3 1.7 mA
Operating Current VCC = V
Start-up Threshold V
Shutdown Threshold V
Shutdown Temperature (TJ) 120 °C
Hysteresis (TJ) 30 °C

)I

CCZ

(Continued)

= 20mA 0.4 0.8 V

OUT

I

= 200mA 2.1 3.0 V

OUT

= –20mA VCC – 2.5 VCC – 1.9 V

OUT

I

= –200mA VCC – 3.0 VCC – 2.2 V

OUT

= 10mA, VCC = 8V 0.8 1.5 V

OUT

= 25mA 12.8 13.5 14.2 V

CC

– 0.5V 15 19 mA

CCZ

– 0.5 V

CCZ

– 3.5 V

CCZ

FUNCTIONAL DESCRIPTION

OVERVIEW

The ML4831 consists of an Average Current controlled
continuous boost Power Factor front end section with a
flexible ballast control section. Start-up and lamp-out retry
timing are controlled by the selection of external timing
components, allowing for control of a wide variety of
different lamp types. The ballast section controls the lamp
power using frequency modulation (FM) with additional
programmability provided to adjust the VCO frequency
range. This allows for the IC to be used with a variety of
different output networks.

POWER FACTOR SECTION

The ML4831 Power Factor section is an average current
sensing boost mode PFC control circuit which is
architecturally similar to that found in the ML4821. For
detailed information on this control architecture, please
refer to Application Note 16 and the ML4821 data sheet.

GAIN MODULATOR

The ML4831 gain modulator provides 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 appears on the positive
terminal of the IA amplifier to form the reference for the
current error amplifier. Please refer to Figure 1.

V

()( .)

ISINE VEA V

[]

≈

MUL

×−

.

417

mA

11

(1)

where: I(SINE) is the current in the dropping resistor,

V(EA) is the output of the error amplifier (Pin 1).

The output of the gain modulator is limited to 1.0V.

5

ML4831

AVERAGE CURRENT AND OUTPUT VOLTAGE
REGULATION

The PWM regulator in the PFC Control section will act to
offset the positive voltage caused by the multiplier output
by producing an offsetting negative voltage on the current
sense resistor at Pin 4. A cycle-by-cycle current limit is
included to protect the MOSFET from high speed current
transients. When the voltage at Pin 4 goes negative by
more than 1V, the PWM cycle is terminated.

For more information on compensating the average
current and boost voltage error amplifier loops, see
ML4821 data sheet.

OVERVOLTAGE PROTECTION AND INHIBIT

The OVP pin serves to protect the power circuit from
being subjected to excessive voltages if the load should
change suddenly (lamp removal). A divider from the high
voltage DC bus sets the OVP trip level. When the voltage
on Pin 18 exceeds 2.75V, the PFC transistors are inhibited.
The ballast section will continue to operate. The OVP
threshold should be set to a level where the power
components are safe to operate, but not so low
as to interfere with the boost voltage regulation loop.

TRANSCONDUCTANCE AMPLIFIERS

The PFC voltage feedback, PFC current sense, and the
loop current amplifiers are all implemented as operational
transconductance amplifiers. They are designed to have
low small signal forward transconductance such that a
large value of load resistor (R1) and a low value ceramic
capacitor (<1µF) can be used for AC coupling (C1) in the
frequency compensation network. The compensation
network shown in Figure 2 will introduce a zero and a
pole at:

f

ZP

18

2.5V

1

==

2

ππ

RC

11 12

–

+

f

1

2

RC

R1

C2

C1

(2)

Figure 2. Compensation Network

7

10

16

17

11

2

4

3

1

18

R(SET)

R(X)/C(X)

VCC

V

REF

GND

IA OUT

IA +

–1V

I(SINE)

EA OUT

EA –/OVP

UNDER-VOLTAGE

AND THERMAL

SHUTDOWN

7K

+

–V

MUL

7K

–

+

MODULATORS

–

2.5V

+

GAIN

LFB OUT

OSC

PREHEAT

TIMER

PWM (PFC)

2.75V

+

–

–

+

OVP

–

+

R

S

Q

Q

T

Q

+

2.5V

V

REF

LAMP F.B.

INTERRUPT

R(T)/C(T)

PFC OUT

–

+

–

OUT A

OUT B

P GND

6

5

9

8

15

14

13

12

Figure 1. ML4831 Block Diagram

6

ML4831

Figure 3 shows the output configuration for the
operational transconductance amplifiers.

CURRENT

MIRROR

IN OUT

gmV

IN

2

IN OUT

CURRENT

MIRROR

io = gmV

IN

IQ –

gmV

IQ +

IN

2

Figure 3. Output Configuration

A DC path to ground or VCC at the output of the
transconductance amplifiers will introduce an offset error.
The magnitude of the offset voltage that will appear at the
input is given by VOS = io/gm. For a io of 1uA and a gm
of 0.08 µmhos the input referred offset will be 12.5mV.
Capacitor C1 as shown in Figure 2 is used to block the
DC current to minimize the adverse effect of offsets.

BALLAST OUTPUT SECTION

The IC controls output power to the lamps via frequency
modulation with non-overlapping conduction. This means
that both ballast output drivers will be low during the
discharging time t

of the oscillator capacitor CT.

DIS

OSCILLATOR

The VCO frequency ranges are controlled by the output of
the LFB amplifier (Pin 6). As lamp current decreases, Pin 6
rises in voltage, causing the C(T) charging current to
decrease, thereby causing the oscillator frequency to
decrease. Since the ballast output network attenuates high
frequencies, the power to the lamp will be increased.

V

R(T)

C(T)

17

8

REF

R(T)/C(T)

5 mA

I

CHG

1.25/3.75

CONTROL

+

–

V

REF

Slew rate enhancement is incorporated into all of the
operational transconductance amplifiers in the ML4831.
This improves the recovery of the circuit in response to
power up and transient conditions. The response to large
signals will be somewhat non-linear as the
transconductance amplifiers change from their low to high
transconductance mode. This is illustrated in Figure 4.

i

O

0

Linear Slope Region

VIN Differential

Figure 4. Transconductance Amplifier Characteristics

CLOCK

t

= 3.75V

V

TH

C(T)

VTL = 1.25V

DIS

t

CHG

Figure 5. Oscillator Block Diagram and Timing

The oscillator frequency is determined by the following
equations:

F

OSC

=

1

tt

+

CHG DIS

and



VIRV

tRCIn

=

CHG T T

REF CH T TL



VIRV



REF CH T TH

+−

+−






(3)

(4)

7

ML4831

The oscillator’s minimum frequency is set when ICH = 0
where:

051.

DIS

.

1

RC

×

TT

This assumes that t

F

OSC

CHG

≅

>> t

When LFB OUT is high, ICH = 0 and the minimum
frequency occurs. The charging current varies according
to two control inputs to the oscillator:

1. The output of the preheat timer

2. The voltage at Pin 6 (lamp feedback amplifier
output)

In preheat condition, charging current is fixed at

25

.

I

CHG PREHEAT()

In running mode, charging current decreases as the V

=

R SET

()

PIN6

rises from 0V to VOH of the LAMP FB amplifier. The
highest frequency will be attained when I
which is attained when V

I

CHG( )

PIN6

0

is at 0V:

5

=

()

R SET

is highest,

CHG

(5)

(6)

(7)

To help reduce ballast cost, the ML4831 includes a
temperature sensor which will inhibit ballast operation if
the IC’s junction temperature exceeds 120°C. In order to
use this sensor in lieu of an external sensor, care should be
taken when placing the IC to ensure that it is sensing
temperature at the physically appropriate point in the
ballast. The ML4831’s die temperature can be estimated
with the following equation:

TT P CW

≅××°65 /

JAD

VCCZ

V

CC

V(ON)

V(OFF)

I

CC

15mA

1.3mA

(9)

t

t

Highest lamp power, and lowest output frequency are
attained when V

is at its maximum output voltage

PIN6

(VOH).
In this condition, the minimum operating frequency of the

ballast is set per (5) above.
For the IC to be used effectively in dimming ballasts with

higher Q output networks a larger CT value and lower R

T

value can be used, to yield a smaller frequency excursion
over the control range (V
to 5mA. Assuming that I

tC

DIS VCO T()

). The discharge current is set

PIN6

>> IRT:

DIS

≅×490

(8)

IC BIAS, UNDER-VOLTAGE LOCKOUT AND THERMAL
SHUTDOWN

The IC includes a shunt regulator which will limit the
voltage at VCC to 13.5 (V

). The IC should be fed with

CCZ

a current limited source, typically derived from the ballast
transformer auxiliary winding. When VCC is below
V

– 0.7V, the IC draws less than 1.7mA of quiescent

CCZ

current and the outputs are off. This allows the IC to start
using a “bleed resistor” from the rectified AC line.

Figure 6. Typical VCC and ICC Waveforms when

the ML4831 is Started with a Bleed Resistor from

the Rectified AC Line and Bootstrapped from an

Auxiliary Winding.

STARTING, RE-START, PREHEAT AND INTERRUPT

The lamp starting scenario implemented in the ML4831
is designed to maximize lamp life and minimize ballast
heating during lamp out conditions.

The circuit in Figure 7 controls the lamp starting scenarios:
Filament preheat and Lamp Out interrupt. C(X) is charged
with a current of I

/4 and discharged through R(X).

R(SET)

The voltage at C(X) is initialized to 0.7V (VBE) at power
up. The time for C(X) to rise to 3.4V is the filament preheat
time. During that time, the oscillator charging current
(I

) is 2.5/R(SET). This will produce a high frequency

CHG

for filament preheat, but will not produce sufficient
voltage to ignite the lamp.

After cathode heating, the inverter frequency drops to F

MIN

causing a high voltage to appear to ignite the lamp. If the
voltage does not drop when the lamp is supposed to have
ignited, the lamp voltage feedback coming into Pin 9 rises
to above V

, the C(X) charging current is shut off and the

REF

inverter is inhibited until C(X) is discharged by R(X) to the

1.2V threshold. Shutting off the inverter in this manner
prevents the inverter from generating excessive heat when
the lamp fails to strike or is out of socket. Typically this
time is set to be fairly long by choosing a large value of R(X).

8

0.625

R(SET)

1.2/3.4

1.2/6.8

–

+

+

–

+

–

R(X)

C(X)

R(X)/C(X)

10

9

INT

6.8

V

REF

Figure 7. Lamp Preheat and Interrupt Timers

HEAT

DIMMING
LOCKOUT

R

Q

S

INHIBIT

ML4831

LFB OUT is ignored by the oscillator until C(X) reaches

6.8V threshold. The lamps are therefore driven to full
power and then dimmed. The C(X) pin is clamped to
about 7.5V.

A summary of the operating frequencies in the various
operating modes is shown below.

Operating Mode Operating Frequency

[F(MAX) to F(MIN)]

Preheat 2

Dimming

Lock-out F(MIN)

Dimming

Control F(MIN) to F(MAX)

R(X)/C(X)

HEAT

DIMMING
LOCKOUT

INT

INHIBIT

6.8

3.4

1.2

.65

0

7.5

Figure 8. Lamp Starting and Restart Timing

9

ML4831

123456789

181716151413121110

ML4831

D1 D3

D2 D4

L

G

N

F1

120V

L1

L2

C2

C1

C3

D8

T1

41

32

R6

R14

C12 C5

D5

D6

R1 R4 R2 R3 R5 R24

C25 C26 C4 C6 C7

R16

R10

R17

C10

+

R7

R11

Q1

D7

C11

+

R12

R13

R9 R8

C13

C14

C24 C15

C16

++

R15

D11 D12

C22

Q2

Q3

T2

5

84

1

C17

R21 R22

T3

2

1

4

5

368

7

10 9

C20

C19

T4

1

4

8

5

41

85

T5

C23

Y

Y

R

R

B

B

D13

C21

R23

APPLICATIONS

POWER FACTOR CORRECTED FLUORESCENT DIMMING LAMP BALLAST

Figure 9. Typical Application: 2-Lamp Isolated Dimming Ballast with Active Power Factor Correction for 120VAC Input

10

TABLE 1: PARTS LIST FOR THE ML4831EVAL EVALUATION KIT

CAPACITORS

QTY. REF. DESCRIPTION MFR. PART NUMBER

2 C1, 2 3.3nF, 125VAC, 10%, ceramic, “Y” capacitor Panasonic ECK-DNS332ME
1 C3 0.33µF, 250VAC, “X”, capacitor Panasonic ECQ-U2A334MV
4 C4, 8, 9, 22 0.1µF, 50V, 10%, ceramic capacitor AVX SR215C104KAA
2 C5, 21 0.01µF, 50V, 10%, ceramic capacitor AVX SR211C103KAA
1 C6 1.5µF, 50V, 2.5%, NPO ceramic capacitor AVX RPE121COG152
2 C7, 12 1µF, 50V, 20%, ceramic capacitor AVX SR305E105MAA
1 C10 100µF, 25V, 20%, electrolytic capacitor Panasonic ECE-A1EFS101
1 C11 100µF, 250V, 20%, electrolytic capacitor Panasonic ECE-S2EG101E
1 C13 4.7µF, 50V, 20%, electrolytic capacitor Panasonic ECE-A50Z4R7
3 C14, 15, 17 0.22µF, 50V, 10%, ceramic capacitor AVX SR305C224KAA
1 C16 1.5µF, 50V, 10%, ceramic capacitor AVX SR151V152KAA

ML4831

1 C19 22nF, 630V, 5%, polypropylene capacitor WIMA MKP10, 22nF, 630V, 5%
1 C20 0.1µF, 250V, 5%, polypropylene capacitor WIMA MKP10, 0.1µF, 250V, 5%
1 C23 0.068µF, 160V, 5%, polypropylene capacitor WIMA MKP4, 68nF, 160V, 5%
1 C24 220µF, 16V, 20%, electrolytic capacitor Panasonic ECE-A16Z220

1 C25 47nF, 50V, 10%, ceramic capacitor AVX SR211C472KAA

1 C26 330pF, 50V, 10%, ceramic capacitor AVX SR151A331JAA

RESISTORS:

1 R1 0.33Ω, 5%, 1/2W, metal film resistor NTE HWD33

1 R2 4.3K, 1/4W, 5%, carbon film resistor Yageo 4.3K-Q

1 R3 47K, 1/4W, 5%, carbon film resistor Yageo 47K-Q

1 R4 12K, 1/4W, 5%, carbon film resistor Yageo 12K-Q

1 R5 20K, 1/4W, 1%, metal film resistor Dale SMA4-20K-1

1 R6 360K, 1/4W, 5%, carbon film resistor Yageo 360K-Q

1 R7 36K, 1W, 5%, carbon film resistor Yageo 36KW-1-ND
3 R8, 22, 11 22Ω, 1/4W, 5%, carbon film resistor Yageo 22-Q

1 R9 402K, 1/4W, 1%, metal film resistor Dale SMA4-402K-1

1 R10 17.8K, 1/4W, 1%, metal film resistor Dale SMA4-17.8K-1

1 R12 475K, 1/4W, 1%, metal film resistor Dale SMA4-475K-1

1 R13 5.49K, 1/4W, 1%, metal film resistor Dale SMA4-5.49K-1

11

ML4831

TABLE 1: PARTS LIST FOR ML4831EVAL EVALUATION KIT

(Continued)

RESISTORS: (Continued)

QTY. REF. DESCRIPTION MFR. PART NUMBER

4 R14, 17, 24, 25 100K, 1/4W, 5%, carbon film resistor Yageo 100K-Q

1 R15 681K, 1/4W, 5%, carbon film resistor Yageo 681K-Q

1 R16 10K, 1/4W, 1%, metal film resistor Dale SMA4-10K-1
1 R21 33Ω, 1/4W, 5%, carbon film resistor Yageo 33-Q

1 R23 25K, pot (for dimming adjustment) Bourns 3386P-253-ND

DIODES:

4 D1, 2, 3, 4 1A, 600V, 1N4007 diode Motorola 1N4007TR

(or 1N5061 as a substitute)

2 D5, 6 1A, 50V (or more), 1N4001 diodes Motorola 1N4001TR

1 D7 3A, 400V, BYV26C or BYT03 400 fast recovery GI BYV26C

or MUR440 Motorola ultra Fast diode

5 D8, 9, 11, 0.1A, 75V, 1N4148 signal diode Motorola 1N4148TR

12, 13

IC’s:

1 IC1 ML4831, Electronic Ballast Controller IC Micro ML4831CP

Linear

TRANSISTORS:

3 Q1, 2, 3 3.3A, 400V, IRF720 power MOSFET IR IR720

MAGNETICS:

1 T1 T1 Boost Inductor, E24/25, 1mH, Custom Coils P/N 5039 or Coiltronics P/N CTX05-12538-1

E24/25 core set, TDK PC40 material
8-pin vertical bobbin (Cosmo #4564-3-419),
Wind as follows:
195 turns 25AWG magnet wire, start pin #1, end pin #4
1 layer mylar tape
14 turns 26AWG magnet wire, start pin #3, end pin #2
NOTE: Gap for 1mH ±5%

1 T2 T2 Gate Drive Xfmr, L

Toroid Magnetics YW-41305-TC
Wind as follows:
Primary = 25 turns 30AWG magnet wire, start pin #1, end pin #4
Secondary = 50 turns 30AWG magnet wire, start pin #5, end pin #8

= 3mH, Custom Coils P/N 5037 or Coiltronics P/N CTX05-12539-1

PRI

12

ML4831

TABLE 1: PARTS LIST FOR ML4831EVAL EVALUATION KIT

(Continued)

MAGNETICS: (Continued)

QTY. REF. DESCRIPTION MFR. PART NUMBER

1 T3 T3 Inductor, L

E24/25 core set, TDK PC40 material
10 pin horizontal bobbin (Plastron #0722B-31-80)
Wind as follows:
1st: 170T of 25AWG magnet wire; start pin #10, end pin #9.
1 layer of mylar tape
2nd: 5T of #32 magnet wire; start pin #2, end pin #1
1 layer of mylar tape
3rd: 3T of #30 Kynar coated wire; start pin #4, end pin #5
4th: 3T of #30 Kynar coated wire; start pin #3, end pin #6
5th: 3T of #30 Kynar coated wire; start pin #7, end pin #8
NOTE: Gap for 1.66mH ±5% (pins 9 to 10)

1 T4 T4 Power Xfmr, L

E24/25 core set, TDK PC40 material
8 pin vertical bobbin (Cosmo #4564-3-419)
Wind as follows:
1st: 200T of 30AWG magnet wire; start pin #1, end pin #4.
1 layer of mylar tape
2nd: 300T of 32AWG magnet wire; start pin #5, end pin #8
NOTE: Gap for inductance primary: (pins 1 to 4) @ 3.87mH ±5%

= 1.66mH, Custom Ciols P/N 5041 or Coiltronics P/N CTX05-12547-1

PRI

= 3.87mH, Custom Ciols P/N 5038 or Coiltronics P/N CTX05-12545-1

PRI

1 T5 T5 Current Sense Inductor, Custom Coils P/N 5040 or Coiltronics P/N CTX05-12546-1

Toroid Magnetics YW-41305-TC
Wind as follows:
Primary = 3T 30AWG magnet coated wire, start pin #1, end pin #4
Secondary = 400T 35AWG magnet wire, start pin #5, end pin #8

INDUCTORS:

2 L1, 2 EMI/RFI Inductor, 600µH, DC resistance = 0.45Ω Prem. SPE116A

Magnetics

FUSES:

1 F1 2A fuse, 5 x 20mm miniature Littlefuse F948-ND

2 Fuse Clips, 5 x 20mm, PC Mount F058-ND

HARDWARE:

1 Single TO-220 Heatsink Aavid Eng. PB1ST-69

2 Double TO-220 Heatsink IERC PSE1-2TC

3 MICA Insulators Keystone 4673K-ND

13

ML4831

PHYSICAL DIMENSIONS inches (millimeters)

Package: P18

18-Pin PDIP

0.890 - 0.910

(22.60 - 23.12)

18

0.045 MIN
(1.14 MIN)
(4 PLACES)

0.170 MAX
(4.32 MAX)

0.125 MIN
(3.18 MIN)

PIN 1 ID

1

0.050 - 0.065
(1.27 - 1.65)

0.016 - 0.022

(0.40 - 0.56)

0.100 BSC

(2.54 BSC)

SEATING PLANE

0.240 - 0.260
(6.09 - 6.61)

0.015 MIN
(0.38 MIN)

0.295 - 0.325
(7.49 - 8.26)

0º - 15º

0.008 - 0.012
(0.20 - 0.31)

ORDERING INFORMATION

PART NUMBER TEMPERATURE RANGE PACKAGE

ML4831CP0°C to 85°CMolded PDIP (P18) (END OF LIFE)

© Micro Linear 1997
Products described in this document may be covered by one or more of the following patents, U.S.: 4,897,611; 4,964,026; 5,027,116; 5,281,862; 5,283,483; 5,418,502; 5,508,570; 5,510,727; 5,523,940;
5,546,017; 5,559,470; 5,565,761; 5,592,128; 5,594,376; Japan: 2598946. Other patents are pending.

Micro Linear reserves the right to make changes to any product herein to improve reliability, function or design.
Micro Linear does not assume any liability arising out of the application or use of any product described herein,
neither does it convey any license under its patent right nor the rights of others. The circuits contained in this
data sheet are offered as possible applications only. Micro Linear makes no warranties or representations as to
whether the illustrated circuits infringe any intellectual property rights of others, and will accept no responsibility
or liability for use of any application herein. The customer is urged to consult with appropriate legal counsel
before deciding on a particular application.

Micro Linear

is a registered trademark of Micro Linear Corporation

2092 Concourse Drive

San Jose, CA 95131

Tel: [phone]

Fax: [phone]

DS4831-01

14