UC3844B, 45B UC2844B, 45B

2

MOTOROLA ANALOG IC DEVICE DATA

MAXIMUM RATINGS

Rating

Symbol

Value

Unit

Total Power Supply and Zener Current

(ICC + IZ)

30

mA

Output Current, Source or Sink (Note 1)

IO

1.0

A

Output Energy (Capacitive Load per Cycle)

W

5.0

µJ

Current Sense and Voltage Feedback Inputs

Vin

– 0.3 to + 5.5

V

Error Amp Output Sink Current

IO

10

mA

Power Dissipation and Thermal Characteristics

D Suffix, Plastic Package, SO–14 Case 751A

Maximum Power Dissipation @ TA = 25°C

Thermal Resistance, Junction–to–Air

D1 Suffix, Plastic Package, SO–8 Case 751

Maximum Power Dissipation @ TA = 25°C

Thermal Resistance, Junction–to–Air

N Suffix, Plastic Package, Case 626

Maximum Power Dissipation @ TA = 25°C

Thermal Resistance, Junction–to–Air

PD

R

θJA

PD

R

θJA

PD

R

θJA

862

145

702

178

1.25

100

mW

°C/W

mW

°C/W

W

°C/W

Operating Junction Temperature

TJ

+150

°C

Operating Ambient Temperature

UC3844B, UC3845B

UC2844B, UC2845B

TA

0 to + 70

– 25 to + 85

°C

Storage Temperature Range

Tstg

– 65 to +150

°C

the operating ambient temperature range that applies [Note 3], unless otherwise noted.)

UC284XB

UC384XB, XBV

Characteristic

Symbol

Min

Typ

Max

Min

Typ

Max

Unit

REFERENCE SECTION

Reference Output Voltage (IO = 1.0 mA, TJ = 25°C)

Vref

4.95

5.0

5.05

4.9

5.0

5.1

V

Line Regulation (VCC = 12 V to 25 V)

Regline

–

2.0

20

–

2.0

20

mV

Load Regulation (IO = 1.0 mA to 20 mA)

Regload

–

3.0

25

–

3.0

25

mV

Temperature Stability

TS

–

0.2

–

–

0.2

–

mV/

°C

Total Output Variation over Line, Load, and Temperature

Vref

4.9

–

5.1

4.82

–

5.18

V

Output Noise Voltage (f = 10 Hz to 10 kHz, TJ = 25°C)

Vn

–

50

–

–

50

–

µV

Long Term Stability (TA = 125°C for 1000 Hours)

S

–

5.0

–

–

5.0

–

mV

Output Short Circuit Current

ISC

–30

–85

–180

–30

–85

–180

mA

OSCILLATOR SECTION

Frequency

TJ = 25°C

TA = Tlow to Thigh

TJ = 25°C (RT = 6.2 k, CT = 1.0 nF)

fOSC

49

48

225

52

–

250

55

56

275

49

48

225

52

–

250

55

56

275

kHz

Frequency Change with Voltage (VCC = 12 V to 25 V)

∆fOSC/∆V

–

0.2

1.0

–

0.2

1.0

%

Frequency Change with Temperature

TA = Tlow to Thigh

∆fOSC/∆T

–

1.0

–

–

0.5

–

%

Oscillator Voltage Swing (Peak–to–Peak)

VOSC

–

1.6

–

–

1.6

–

V

Discharge Current (VOSC = 2.0 V)

TJ = 25°C

TA = Tlow to Thigh (UC284XB, UC384XB)

Idischg

7.8

7.5

–

8.3

–

–

8.8

8.8

–

7.8

7.6

7.2

8.3

–

–

8.8

8.8

8.8

mA

NOTES: 1. Maximum package power dissipation limits must be observed.

2. Adjust VCC above the Startup threshold before setting to 15 V.

3. Low duty cycle pulse techniques are used during test to maintain junction temperature as close to ambient as possible.

Tlow =0°C for UC3844B, UC3845B

Thigh =+ 70°C for UC3844B, UC3845B

=– 25

°C for UC2844B, UC2845B

= + 85

°C for UC2844B, UC2845B

=– 40

°C for UC3844BV, UC3845BV

= +105

°C for UC3844BV, UC3845BV