PDF UC3842B Data sheet ( Hoja de datos )

Número de pieza	UC3842B
Descripción	(UC3842B / UC3843B) HIGH PERFORMANCE CURRENT MODE CONTROLLERS
Fabricantes	Motorola Semiconductors
Logotipo
Hay una vista previa y un enlace de descarga de UC3842B (archivo pdf) en la parte inferior de esta página. Total 16 Páginas
No Preview Available ! www.DataSheet4U.com Order this document by UC3842B/D UC3842B, 43B UC2842B, 43B High Performance Current Mode Controllers The UC3842B, UC3843B series are high performance fixed frequency current mode controllers. They are specifically designed for Off–Line and dc–to–dc converter applications offering the designer a cost–effective solution with minimal external components. These integrated circuits feature a trimmed oscillator for precise duty cycle control, a temperature compensated reference, high gain error amplifier, current sensing comparator, and a high current totem pole output ideally suited for driving a power MOSFET. Also included are protective features consisting of input and reference undervoltage lockouts each with hysteresis, cycle–by–cycle current limiting, programmable output deadtime, and a latch for single pulse metering. These devices are available in an 8–pin dual–in–line and surface mount (SO–8) plastic package as well as the 14–pin plastic surface mount (SO–14). The SO–14 package has separate power and ground pins for the totem pole output stage. The UCX842B has UVLO thresholds of 16 V (on) and 10 V (off), ideally suited for off–line converters. The UCX843B is tailored for lower voltage applications having UVLO thresholds of 8.5 V (on) and 7.6 V (off). • Trimmed Oscillator for Precise Frequency Control • Oscillator Frequency Guaranteed at 250 kHz • Current Mode Operation to 500 kHz • Automatic Feed Forward Compensation • Latching PWM for Cycle–By–Cycle Current Limiting • Internally Trimmed Reference with Undervoltage Lockout • High Current Totem Pole Output • Undervoltage Lockout with Hysteresis • Low Startup and Operating Current Simplified Block Diagram VCC 7(12) Vref 8(14) R 5.0V Reference R Vref Undervoltage Lockout RT/CT Oscillator 4(7) Voltage Feedback + Input – 2(3) Error Output Amplifier Compensation www.D1a(1)taSheet4U.com Gnd 5(9) Latching PWM VCC Undervoltage Lockout Pin numbers in parenthesis are for the D suffix SO–14 package. VC 7(11) Output 6(10) Power Ground 5(8) Current Sense 3(5) Input HIGH PERFORMANCE CURRENT MODE CONTROLLERS N SUFFIX PLASTIC PACKAGE CASE 626 D1 SUFFIX PLASTIC PACKAGE CASE 751 (SO–8) 8 1 8 1 D SUFFIX PLASTIC PACKAGE CASE 751A (SO–14) 14 1 PIN CONNECTIONS Compensation 1 Voltage Feedback 2 Current Sense 3 RT/CT 4 8 Vref 7 VCC 6 Output 5 Gnd (Top View) Compensation 1 NC 2 Voltage Feedback 3 NC 4 Current Sense 5 NC 6 RT/CT 7 14 Vref 13 NC 12 VCC 11 VC 10 Output 9 Gnd 8 Power Ground (Top View) ORDERING INFORMATION Device Operating Temperature Range Package UC384XBD SO–14 UC384XBD1 UC384XBN TA = 0° to +70°C SO–8 Plastic UC284XBD SO–14 UC284XBD1 TA = – 25° to +85°C UC284XBN SO–8 Plastic UC384XBVD SO–14 UC384XBVD1 TA = – 40° to +105°C UC384XBVN SO–8 Plastic X indicates either a 2 or 3 to define specific device part numbers. MOTOROLA ANALOG IC DEVICE DATA © Motorola, Inc. 1996 Rev 1 1 1 page www.DataSheet4U.com 2.55 V 2.50 V UC3842B, 43B UC2842B, 43B Figure 5. Error Amp Small Signal Transient Response Figure 6. Error Amp Large Signal Transient Response VCC = 15 V AV = –1.0 TA = 25°C 3.0 V VCC = 15 V AV = –1.0 TA = 25°C 2.5 V 2.45 V 0.5 µs/DIV 2.0 V 1.0 µs/DIV Figure 7. Error Amp Open Loop Gain and Phase versus Frequency 100 0 VCC = 15 V 80 Gain VO = 2.0 V to 4.0 V RL = 100 K 30 TA = 25°C 60 60 40 90 Phase 20 120 0 – 20 10 150 180 100 1.0 k 10 k 100 k 1.0 M 10 M f, FREQUENCY (Hz) Figure 8. Current Sense Input Threshold versus Error Amp Output Voltage 1.2 VCC = 15 V 1.0 0.8 TA = 25°C 0.6 TA = 125°C 0.4 TA = –55°C 0.2 0 0 2.0 4.0 6.0 8.0 VO, ERROR AMP OUTPUT VOLTAGE (V) Figure 9. Reference Voltage Change versus Source Current 0 ÄÄÄÄVCC = 15 V ÄÄÄÄ– 4.0 – 8.0 ÄÄÄÄ–12 TA = 125°C ÄÄÄÄÄÄTA = –55°C –16 ÄÄÄÄÄÄÄÄ–20 TA=25°C – 24 0 20 40 60 80 100 120 www.DataSIrehf,eREeFEt4REUNC.EcSoOmURCE CURRENT (mA) Figure 10. Reference Short Circuit Current versus Temperature 110 ÄÄÄÄVCC = 15 V ÄÄÄÄRL ≤ 0.1 Ω 90 70 50 – 55 – 25 0 25 50 75 TA, AMBIENT TEMPERATURE (°C) 100 125 MOTOROLA ANALOG IC DEVICE DATA 5 5 Page www.DataSheet4U.com UC3842B, 43B UC2842B, 43B Figure 20. External Clock Synchronization Vref 8(14) RT R Bias R External Sync Input CT 0.01 47 4(7) 2(3) Osc + EA 2R R 1(1) The diode clamp is required if the Sync amplitude is large enough to cause the bottom side of CT to go more than 300 mV below ground. 5(9) Figure 21. External Duty Cycle Clamp and Multi–Unit Synchronization RA 8 RB 6 5.0k 5 5.0k 2 C 5.0k 1 4 R Q S MC1455 8(14) 3 4(7) 7 2(3) 1(1) R Bias R Osc + EA 2R R f + (RA 1.44 ) 2RB)C D(max) + RA )RB 2RB To Additional UCX84XBs 5(9) Figure 22. Adjustable Reduction of Clamp Level VCC 7(12) Vin 8(14) R Bias 5.0V Ref R + – + – 7(11) 4(7) R2 2(3) Osc + 1.0 mA VClamp EA 2R R 1.0V S Q R Comp/Latch 6(10) 5(8) 1(1) R1 5(9) 3(5) 1.67 ǒ ǓVClamp ≈ R2 R1 ) 1 ǒ Ǔ)+ 0.33x10–3 R1R2 R1 R2 Where: 0 ≤ VClamp ≤ 1.0 V [Ipk(max) VClamp RS Q1 RS Figure 23. Soft–Start Circuit 8(14) 4(7) 2(3) 1.0M R Bias R Osc + 1.0mA EA 5.0V Ref + – 2R R 1.0V S Q R 1(1) C tSoft–Start ≈ 3600C in µF 5(9) www.DataSheet4U.com MOTOROLA ANALOG IC DEVICE DATA 11 11 Page

Páginas	Total 16 Páginas
PDF Descargar	[ Datasheet UC3842B.PDF ]

Hoja de datos destacado

Número de pieza	Descripción	Fabricantes
UC3842	Current Mode PWM Controller (Rev. C)	Texas Instruments
UC3842	Current-mode PWM controller	Philips
UC3842	SMPS Controller	Fairchild
UC3842	CURRENTMODE PWM CONTROLLER	ST Microelectronics

Número de pieza	Descripción	Fabricantes
SLA6805M	High Voltage 3 phase Motor Driver IC.	Sanken
SDC1742	12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters.	Analog Devices

DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares,
permitiéndote verlos en linea o descargarlos en PDF.

DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar