Temporizador

Order this document by MC34129/D

High Performance Current Mode Controllers
The MC34129/MC33129 are high performance current mode switching regulators specifically designed for use in low power digital telephone applications. These integrated circuits feature a unique internal fault timer that provides automatic restart for overload recovery. For enhanced system efficiency, a start/runcomparator is included to implement bootstrapped operation of VCC. Other functions contained are a temperature compensated reference, reference amplifier, fully accessible error amplifier, sawtooth oscillator with sync input, pulse width modulator comparator, and a high current totem pole driver ideally suited for driving a power MOSFET. Also included are protective features consisting of soft–start,undervoltage lockout, cycle–by–cycle current limiting, adjustable deadtime, and a latch for single pulse metering. Although these devices are primarily intended for use in digital telephone systems, they can be used cost effectively in many other applications. • Current Mode Operation to 300 kHz

MC34129 MC33129
HIGH PERFORMANCE CURRENT MODE CONTROLLERS
SEMICONDUCTOR TECHNICAL DATA

14 1

PSUFFIX PLASTIC PACKAGE CASE 646

• • • • • • • • •

Automatic Feed Forward Compensation Latching PWM for Cycle–by–Cycle Current Limiting Continuous Retry after Fault Timeout Soft–Start with Maximum Peak Switch Current Clamp Internally Trimmed 2% Bandgap Reference High Current Totem Pole Driver Input Undervoltage Lockout Low Startup and Operating Current Direct Interface with Motorola SENSEFETProducts
Drive Output Drive Ground Ramp Input
14 1

D SUFFIX PLASTIC PACKAGE CASE 751A (SO–14)

PIN CONNECTIONS
1 2 3 14 VCC 13 Start/Run Output 12 CSoft–Start Feedback/ 11 PWM Input Error Amp 10 Inverting Input 9 Error Amp Noninverting Input 8 Vref 1.25 V (Top View)

Simplified Block Diagram
Start/Run 12 Soft–Start and Fault Timer Undervoltage Lockout 1.25V Reference Gnd 7 Error Amp 6 X2Latching PWM RT/CT Sync/Inhibit Input 5 4 Oscillator 9 Noninverting Input + 10 – Inverting Input 11 Feedback/ 1 PWM Input Drive Out 2 Drive Gnd 3 Ramp Input 13 Start/Run Output VCC

Sync/Inhibit 4 Input RT/CT 5 Vref 2.5 V 6

CSoft–Start

14

Gnd 7

8

Vref 1.25V

ORDERING INFORMATION
Device MC34129D MC34129P MC33129D MC33129P Operating Temperature Range TA = 0° to +70°C TA = – 40°to +85°C Package SO–14 Plastic DIP SO–14 Plastic DIP
Rev 1

Vref 2.5V

© Motorola, Inc. 1996

MOTOROLA ANALOG IC DEVICE DATA

1

MC34129 MC33129
MAXIMUM RATINGS
Rating VCC Zener Current Start/Run Output Zener Current Analog Inputs (Pins 3, 5, 9, 10, 11, 12) Sync Input Voltage Drive Output Current, Source or Sink Current, Reference Outputs (Pins 6, 8) Power Dissipation and ThermalCharacteristics D Suffix, Plastic Package Case 751A Maximum Power Dissipation @ TA = 70°C Thermal Resistance, Junction–to–Air P Suffix, Plastic Package Case 646 Maximum Power Dissipation @ TA = 70°C Thermal Resistance, Junction–to–Air Operating Junction Temperature Operating Ambient Temperature MC34129 MC33129 Storage Temperature Range Symbol IZ(VCC) IZ(Start/Run) – Vsync IDRV Iref Value 50 50 –0.3to 5.5 –0.3 to VCC 1.0 20 Unit mA mA V V A mA

PD RθJA PD RθJA TJ TA

552 145 800 100 +150 0 to +70 –40 to +85

mW °C/W mW °C/W °C °C

Tstg

–65 to +150

°C

ELECTRICAL CHARACTERISTICS (VCC = 10 V, TA = 25°C [Note 1], unless otherwise noted.)
Characteristics REFERENCE SECTIONS Reference Output Voltage, TA = 25°C 1.25 V Ref., IL = 0 mA 2.50 V Ref., IL = 1.0 mA Reference OutputVoltage, TA = Tlow to Thigh 1.25 V Ref., IL = 0 mA 2.50 V Ref., IL = 1.0 mA Line Regulation (VCC = 4.0 V to 12 V) 1.25 V Ref., IL = 0 mA 2.50 V Ref., IL = 1.0 mA Load Regulation 1.25 V Ref., IL = –10 µA to +500 µA 2.50 V Ref., IL = –0.1 mA to +1.0 mA ERROR AMPLIFIER Input Offset Voltage (Vin = 1.25 V) TA = 25°C TA = Tlow to Thigh Input Offset Current (Vin = 1.25 V) Input Bias Current (Vin = 1.25 V) TA...