FEATURES
1 2 3 4 5 6 7 816 15 14 13 12 11 10 9
1IN+
1IN−FEEDBACK
DTC
CT
RT
GND
C12IN+
2IN−
REF
OUTPUT CTRL V CC
C2
E2
E1
D, DB, N, NS, OR PW PACKAGE
(TOP VIEW) DESCRIPTION TL494
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074E–JANUARY1983–REVISED FEBRUARY2005
•Complete PWM Power-Control Circuitry
•Uncommitted Outputs for200-mA Sink or
Source Current
•Output Control Selects Single-Ended or
Push-Pull Operation
•Internal Circuitry Prohibits Double Pul at
Either Output
妾室养儿记•Variable Dead Time Provides Control Over
曾经也只是曾经Total Range
•Internal Regulator Provides a Stable5-V
Reference Supply With5%Tolerance
闹钟功能
•Circuit Architecture Allows Easy
Synchronization
The TL494incorporates all the functions required in the construction of a pul-width-modulation(PWM)control circuit on a single chip.Designed primarily for power-supply control,this device offers the flexibility to tailor the power-supply control circuitry to a specific application.
The TL494contains two error amplifiers,an on-chip adjustable oscillator,a dead-time control(DTC)co
mparator, a pul-steering control flip-flop,a5-V,5%-precision regulator,and output-control circuits.
The error amplifiers exhibit a common-mode voltage range from–0.3V to V CC–2V.The dead-time control comparator has a fixed offt that provides approximately5%dead time.The on-chip oscillator can be bypasd by terminating RT to the reference output and providing a sawtooth input to CT,or it can drive the common circuits in synchronous multiple-rail power supplies.
The uncommitted output transistors provide either common-emitter or emitter-follower output capability.The TL494provides for push-pull or single-ended output operation,which can be lected through the output-control function.The architecture of this device prohibits the possibility of either output being puld twice during push-pull operation.
The TL494C is characterized for operation from0°C to70°C.The TL494I is characterized for operation from –40°C to85°C.
AVAILABLE OPTIONS
PACKAGED DEVICES(1)
SHRINK SMALL THIN SHRINK T A SMALL OUTLINE PLASTIC DIP SMALL OUTLINE
OUTLINE SMALL OUTLINE
(D)(N)(NS)
(DB)(PW) 0°C to70°C TL494CD TL494CN TL494CNS TL494CDB TL494CPW –40°C to85°C TL494ID TL494IN———
(1)The D,DB,NS,and PW packages are available taped and reeled.Add the suffix R to device ,TL494CDR).
Plea be aware that an important notice concerning availability,standard warranty,and u in critical applications of Texas
GND
V CC
历史答题
C1E1
C2E2
FEEDBACK
REF
TL494
PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074E–JANUARY 1983–REVISED FEBRUARY 2005
FUNCTION TABLE
INPUT TO OUTPUT FUNCTION OUTPUT CTRL V I =GND Single-ended or parallel output V I =V ref
Normal push-pull operation
男生抱女生
FUNCTIONAL BLOCK DIAGRAM
Absolute Maximum Ratings(1) Recommended Operating Conditions
TL494 PULSE-WIDTH-MODULATION CONTROL CIRCUITS
SLVS074E–JANUARY1983–REVISED FEBRUARY2005
铃声响起over operating free-air temperature range(unless otherwi noted)
MIN MAX UNIT V CC Supply voltage(2)41V
V I Amplifier input voltage V CC+0.3V
V O Collector output voltage41V
I O Collector output current250mA
D package73
DB package82
θJA Package thermal impedance(3)(4)N package67°C/W
NS package64
PW package108 Lead temperature1,6mm(1/16inch)from ca for10conds260°C
T stg Storage temperature range–65150°C (1)Stress beyond tho listed under"absolute maximum ratings"may cau permanent damage to the device.The are stress ratings
only,and functional operation of the device at the or any other conditions beyond tho indicated under"recommended operating conditions"is not implied.Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2)All voltages are with respect to the network ground terminal.
(3)Maximum power disipation is a function of T J(max),θJA,and T A.The maximum allowable power dissipation at any allowable ambient
temperatire is P D=(T J(max)–T A)/θJA.Operating at the absolute maximum T J of150°C can affect reliability.
猪肉饺子馅的做法(4)The package thermal impedance is calculated in accordance with JESD51-7.
MIN MAX UNIT V CC Supply voltage740V
英语节
V I Amplifier input voltage–0.3V CC–2V
V O Collector output voltage40V Collector output current(each transistor)200mA
Current into feedback terminal0.3mA f OSC Oscillator frequency1300kHz C T Timing capacitor0.4710000nF
R T Timing resistor 1.8500kΩ
TL494C070
T A Operating free-air temperature°C
TL494I–4085
