View NTE1723_1290278.PDF datasheet online --- IC-ON-LINE

Datasheet File OCR Text:

NTE1721 & NTE1723 Integrated Circuit Pulse Width Modulator (PWM) Regulator
Description: The NTE1721 and NTE1723 are pulse width modulator control-circuits designed to offer improved performance and lowered external parts count when implemented for controlling all types of switching power supplies. The no-chip +5.1V reference is trimmed to 1% and the input common-mode range of the errror amplifier includes the reference voltage, thus eliminating the need for external divider resistors. A sync input to the oscillator enables multiple units to be slaved or a single unit to be synchronized to an external system clock. A wide range of dead time can be programmed by a single resistor connected between the CT and the Discharge pins. These devices also feature a built-in soft-start circuitry, requiring only an external timing capacitor. A shutdown pin controls both the soft- start circuitry and the output stages, provided instantaneous turn-off through the PWM latch with pulsed shutdown, as well as soft-start recycle with longer shutdown commands. The under voltage lockout inhibits the outputs and the changing of the soft-start capacitor when VCC is below nominal. The output stages are totem-pole design capable of sinking and sourcing in excess of 200mA. The output stages of the NTE1721 features NOR logic resulting in a low output for an off state while the NTE1723 utilizes OR logic which gives a high output when off. Features: D 8V to 35V Operation D +5.1V 1% Trimmed Reference D 100Hz to 400kHz Oscillator Range D Separate Oscillator Sync Pin D Adjustable Dead Time Control D D D D Input Undervoltage Lockout Latching PWM to Prevent Multiple Pulses Pulse-by-Pulse Shutdown Dual Source/Sink Outputs: 400mA Peak
Absolute Maximum Ratings: (Note 1) Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V Collector Supply Voltage, VC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +40V Logic Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +5.5V Analog Inputs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC Output Current, Source or Sink, IO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500mA Reference Output Current, Iref . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50mA Oscillator Charging Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5mA Power Dissipation (TA = +25C), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1000mW Derate Above 50C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mW/C Power Dissipation (TC = +25C), PD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2000mW Derate Above 25C . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16mW/C Operating Junction Temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +150C Storage Temperature Range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55 to +125C Thermal Resistance, Junction-to-Ambient, RthJA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 100C/W Thermal Resistance, Junction-to-Case, RthJC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 60C/W Lead Temperature (During Soldering, 10sec), TL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . +300C Note 1 Values beyond which damage may occur
Recommended Operating Conditions:
Parameter Supply Voltage Collector Supply Voltage Output Sink/Source Current Steady State Peak Reference Load Current Oscillator Frequency Range Oscillator Timing Resistor Oscillator Timing Capacitor Deadtime Resistor Range Operating Ambient Temperature Range Iref fosc RT CT RD TA Symbol VCC VC IO Min 8.0 4.5 0 0 0 0.1 2.0 0.001 0.5 0 Typ - - - - - - - - - - Max 35.0 35.0 100 400 20 400 150 0.2 - 70 Unit V V mA mA mA kHz k F C
Electrical Characteristics: (VCC = +20V, TA = 0 to +70C unless otherwise specified)
Parameter Reference Section Reference Output Voltage Line Regulation Load Regulation Temperature Stability Total Output Variation (Includes Line and Load Regulation over Temperature Short Circuit Current Output Noise Voltage Long Term Stability Vref Regline Regload Vref/T Vref TJ = +25C +8V VCC +35V 0mA IL 20mA 5.0 - - - 4.95 5.1 10 20 20 - 5.2 20 50 - 5.25 V mV mV mV V Symbol Test Conditions Min Typ Max Unit
ISC Vn S
Vref = 0V, TJ = +25C 10Hz f 10kHz, TJ = +25C TJ = +25C, Note 2 TJ = +25C
- - -
80 40 20 2 1 3 50 - 2.0 3.5 0.5 2.0 1.0
100 200 50 6 2 - - - 2.2 - 1.0 2.8 2.5
mA Vrms mV/kHr
Oscillator Section (Tested at fosc = 40kHz, RT = 3.6k, CT = 0.001F, RD = 0 unless otherwise specified) Initial Accuracy Frequency Stability with Voltage Frequency Stability with Temperature Minimum Frequency Maximum Frequency Current Mirror Clock Amplitude Clock Width Sync Threshold Sync Input Current Error Amplifier Section (VCM = +5.1V) Input Offset Voltage Input Bias Current VIO IIB - - 2.0 1.0 10.0 10.0 mV A Sync Voltage = +3.5V TJ = +25C fosc/VCC fosc/T fmin fmax RT = 150k, CT = 0.2F RT = 2k, CT = 1.0nF IRT = 2mA - - - - 400 1.7 3.0 0.3 1.2 - % % % Hz kHz mA V s V mA +8V VCC +35V
Note 2. Since long term stability cannot be measured on each device before shipment, this specification is an engineering estimate of average stability from lot to lot.
Electrical Characteristics (Cont'd): (VCC = +20V, TA = 0 to +70C unless otherwise specified)
Parameter Symbol Test Conditions RL 10M Min Typ Max Unit Error Amplifier Section (Cont'd) (VCM = +5.1V) DC Open Loop Gain Low Level Output Voltage High Level Output Voltage Common Mode Rejection Ratio Power Supply Rejection Ratio PWM Comparator Section Minimum Duty Cycle Maximum Duty Cycle Input Threshold, Zero Duty Cycle Input Threshold, Maximum Duty Cycle Input Bias Current Soft-Start Section Soft-Start Current Soft-Start Voltage Shutdown Input Current Output Drivers (Each Output, VCC = +20V) Output Low Level VOL VOH VUL IC(leak) tr tf tds ICC Isink = 20mA Isink = 100mA Output High Level Isink = 20mA Isink = 100mA Under Voltage Lockout Collector Leakage Rise Time Fall Time Shutdown Delay Supply Current V8 and V9 = High VC = +35V, Note 3 CL = 1.0nF, TJ = +25C CL = 1.0nF, TJ = +25C VDS = +3V, CS = 0, TJ = +25C VCC = +35V - - 18 17 6.0 - - - - - 0.2 1.0 19 18 7.0 - 100 50 0.2 14 0.4 2.0 - - 8.0 200 600 300 0.5 20 V V V V V A ns ns s mA Vshutdown = 0V Vshutdown = 2.0V Vshutdown = 2.5V 25 - - 50 0.4 0.4 80 0.6 1.0 A V mA IIB DCmin DCmax VTH fosc = 40kHz, RT = 3.6k, CT = 0.01F, RD = 0 - 45 0.6 - - - 49 0.9 3.3 0.05 0 - - 3.6 1.0 % % V V A AVOL VOL VOH CMRR PSRR +1.5V VCM +5.2V +8V VCC +35V 60 - 3.8 60 50 75 0.2 5.6 75 60 - 0.5 - - - dB V V dB dB
Note 3.Applies to NTE1721 Only, due to polarity of output pulses. Application Information (Shutdown Options): Since both the compensation and soft-start terminals (Pin9 and Pin8) have current source pull-ups, either can readily accept a pull-down signal which only has to sink a maximum of 100A to turn off the outputs. This is subject to the added requirement of discharging whatever external capacitance may be attached to these pins. An alternate approach is the use of the shutdown circuitry of Pin10 which has been improved to enhance the available shutdown options. Activating this circuit by applying a positive signal on Pin10 performs two functions: the PWM latch is immediately set providing the fastest turn-off signal to the outputs; and a 150A current sink begins to discharge the external soft-start capacitor. If the shutdown command is short, the PWM signal is terminated without significant discharge of the soft-start capacitor, thus, allowing, for example, a convenient implementation of pulse-by-pulse current limiting. Holding Pin10 high for a longer duration, however, will ultimately discharge this external capacitor, recycling slow turn-on upon release. Pin10 should not be left floating as noise pickup could conceivably interrupt normal operation.
Pin Connection Diagram
Invert Input 1 Non-Invert Input 2 Sync 3 OSC Output 4 CT RT 5 6
16 Vref 15 VIN 14 Output B 13 VC 12 GND 11 Output A 10 Shutdown 9 Compensation
Discharge 7 Soft-Start 8
16
9
1
8
.870 (22.0) Max
.260 (6.6) Max .200 (5.08) Max
.100 (2.54) .700 (17.78)
.099 (2.5) Min

▲Up To Search▲

Price & Availability of NTE1723

	To Download NTE1723 Datasheet File
If you can't view the Datasheet, Please click here to try to view without PDF Reader .