Texas Instruments 8551502VA, 85515022A Datasheet

BLOCK DIAGRAM

UC1526A
UC2526A
UC3526A

Regulating Pulse Width Modulator

FEATURES

• Reduced Supply Current

• Oscillator Frequency to 600kHz

• Precision Band-Gap Reference

• 7 to 35V Operation

• Dual 200mA Source/Sink Outputs

• Minimum Output Cross-Conduction

• Double-Pulse Suppr ession Logic

• Under-Voltage Lockout

• Programmable Soft -Start

• Thermal Shutdown

• TTL/CMOS Compatible L ogic P orts

• 5 Volt Operation (V

IN = VC = V REF = 5.0V)

DESCRIPTION

The UC1526A Series are improved-performance pulse-width modu­lator circuits intended for direct replacement of equivalent non- “A”
versions in all applications. Higher freq uency operation has been
enhanced by several significant improvements including: a more ac­curate oscillator with less minimum dead time, reduced circuit de­lays (particularly i n current limiting), and an improved output stage
with negligible cross-condu ction current. Additional improvements
include the incorporation of a precisi on, band-g ap reference gener­ator, reduced overall supply current, and the addition of thermal
shutdown protection.

Along with these improvements, the UC1526A Series retains the
protective features of under-voltage lockou t, soft-start, digital cur­rent limiting, double pulse suppression logic, and adjustable
deadtime. For ease of interfacing, all digital control ports are TTL
compatible with active low logic.

Five volt (5V) operation is possible for “logic level” applications by
connecting V

IN, VC and VREF to a precision 5V input supply. Consult

factory for additional information.

6/93

RECOMMENDED OPERATING CONDITIONS

(Note 3)

Input Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +7V to +35V

Collector Supply Voltage . . . . . . . . . . . . . . . . . . +4.5V to +35V

Sink/Source Load Cur ren t (each output ) . . . . . . . . 0 to 100mA

Reference Load Cur re nt. . . . . . . . . . . . . . . . . . . . . . 0 to 20mA

Oscillator Frequency Range. . . . . . . . . . . . . . . . 1Hz to 600kHz

Oscillator Timing Resistor. . . . . . . . . . . . . . . . . . . 2k Ω to 150kΩ

Oscillator Timing Capacito r. . . . . . . . . . . . . . . . . 400pF to 20µF

Available Deadtime Range at 40kHz . . . . . . . . . . . . 1% to 50%

Operating Am bient Temper at ur e Range

UC1526A. . . . . . . . . . . . . . . . . . . . . . . . . . . . -55°C to +125°C

UC2526A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . -25°C to +85°C

UC3526A. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to +70°C

ABSOLUTE MAXI MUM RATING S (Note 1, 2)

Input Voltage (+VIN) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V

Collector Supply Voltage (+V

C) . . . . . . . . . . . . . . . . . . . . . +40V

Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V t o +5.5 V

Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +V

IN

Source/ Sin k Load Curr ent (each out pu t) . . . . . . . . . . . . 200mA

Referen ce Loa d Curr ent. . . . . . . . . . . . . . . . . . . . . . . . . . 50mA

Logic Sink Curren t . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15mA

Power Dissipation at T

A = +25°C (Note 2) . . . . . . . . . 1000mW

Power Dissipation at T

C = +25°C (Note 2). . . . . . . . . . 3000mW

Operating Junct ion Te mp era ture . . . . . . . . . . . . . . . . . . +150°C

Storage Temperature Range . . . . . . . . . . . . . . -65°C to +150°C

Lead Tempera tu re (solder ing, 10 seconds ). . . . . . . . . . +300°C

CONNECTION DIAGRAMS

PACKAGE PIN FUNCTION

FUNCTION PIN

N/C 1
+ERROR 2

-ERROR 3
COMP. 4
C

SS 5

RESET 6

- CURRENT SENSE 7
+ CURRENT SENSE 8
SHUTDOWN 9
R

TIMING 10

C

T 11

R

D 12

SYNC 13
OUTPUT A 14
V

C 15

N/C 16
GROUND 17
OUTPUT B 18
+V

IN 19

V

REF 20

PLCC-20, LCC- 20
(TOP VIEW)
Q and L Packages

DIL-18, SOIC-18 (TOP VIEW)
J or N Package, DW Package

Note 1: Values beyond which damage may oc cur.
Note 2: Consult pa ckag ing Sect ion of Dat aboo k for ther mal

limitations and considerations of package.

Note 3: Range over which the device is functional and

parame te r limit s are guar ant eed .

UC1526A
UC2526A
UC3526A

2

PARAMETER TEST CONDITIONS

UC1526A / UC2526A UC3526A

UNITS

MIN TYP MAX MIN TYP MAX

Reference Sec tion (Note 4)

Output Volt age T

J = +25°C 4.95 5.00 5.05 4.90 5.00 5.10 V

Line Regulation +V

IN = 7 to 35V 2 10 2 15 mV

Load Regulation I

L = 0 to 20mA 5 20 5 20 mV

Temperature Stability Over Operating T

J (Note 5) 15 50 15 50 mV

Total Output Voltage
Range

Over Recommended Op era ting
Conditio ns

4.90 5.00 5.10 4.85 5.00 5.15 V

Short Circuit Current V

REF = 0V 25 50 100 25 50 100 mA

Under-Voltage Lockout

RESET Output Voltage VREF = 3.8V 0.2 0.4 0.2 0.4 V

VREF = 4.7V 2.4 4.7 2.4 4.8 V

Oscillato r Sect io n (Note 6)

Initial Accuracy T

J = +25°C ±3 ±8 ±3 ±8%

Voltage Stability +V

IN = 7 to 35V 0.5 1 0.5 1 %

Temperature Stability Over Operating T

J (Note 5) 26 13%

Minimum Freque ncy R

T = 150kΩ, CT = 20µF (Note 5) 1 1 Hz

Maximum Frequency R

T = 2kΩ, CT = 470pF 5 50 650 kHz

Sawtooth Peak Voltage +V

IN = 35V 3.0 3.5 3.0 3.5 V

Sawtooth Valley Voltage +V

IN =7V 0.5 1.0 0.5 1.0 V

SYNC Pulse Width TJ = 25°C, R L = 2. 7 kΩ to V

REF

1.1 1.1 µs

Error Ampl i fier Section (Note 7)

Input Offs et Vo lta g e R

S ≤ 2kΩ 25 210mV

Input Bias Cur ren t -350 -1000 -350 -2000 nA
Input Offs et Cu rr ent 35 100 35 200 nA
DC Open Loop Gain R

L ≥ 10MΩ 64 72 60 72 dB

HIGH Output Voltage V

PIN 1 - VPIN 2 ≥ 150mV, ISOURCE = 100µA 3.6 4.2 3.6 4.2 V

LOW Output Voltage V

PIN 2 - VPIN 1 ≥ 150 mV, ISINK = 100µA 0.2 0.4 0.2 0.4 V

Common Mode Rejec tion R

S ≤ 2kΩ 70 94 70 94 dB

Supply Voltage Rejection +V

IN = 12 to 18V 66 80 66 80 dB

PWM Comparator (Note 6)

Minimum Duty Cycle V

COMPENSATION = +0.4V 0 0 %

Maximum Duty Cycle V

COMPENSATION = +3.6V 45 49 45 49 %

Digital Ports (

SYNC, SHUTDOWN, and RESET)

HIGH Output Voltage I

SOURCE = 40µA 2.4 4.0 2.4 4.0 V

LOW Output Voltage I

SINK = 3.6mA 0.2 0.4 0.2 0.4 V

HIGH Input Current V

IH = +2.4V -125 -200 -125 -200 µA

LOW Input Current V

IL = +0.4V -225 -36 0 -225 -36 0 µA

Shutdown Delay From Pin 8, T

J = 25°C 160 160 ns

Current Limit Compar ato r (Note 8)

Sense Voltage R

S ≤ 50Ω 90 100 110 80 100 120 mV

Input Bias Cur ren t -3 -10 -3 -10 µA
Shutdown Delay From pin 7, 100mV O ver driv e, T

J = 25°C 2 60 260 ns

+V

IN = 15V, and over operating ambient temperature, unless ot herwise specified TA = TJ.

ELECTRICAL CHARACTERISTICS:

Note 4: I

L =

0mA.
Note 5: Guaranteed by design, not 100% tested in product ion.
Note 6: F

OSC

= 40kHz, (RT = 4.12 kΩ ± 1%, CT = 0.01µF± 1%,

R

D

= 0 Ω).

Note 7: V

CM

= 0 to +5.2V

Note 8: V

CM

= 0 to +12V.

Note 9: V

C

= +15V .

Note 10:V

IN

= +35V , RT = 4.12kΩ.

UC1526A
UC2526A
UC3526A

3