ON Manuals

The LM2574 series of regulators are monolithic integrated circuits ideally suited for easy and convenient design of a step−down switching regulator (buck converter). All circuits of this series are capable of driving a 0.5 A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3 V, 5.0 V, 12 V, 15 V, and an adjustable output version. These regulators were designed to minimize the number of external components to simplify the power supply design. Standard series of inductors optimized for use with the LM2574 are offered by several different inductor manufacturers. Since the LM2574 converter is a switch−mode power supply, its efficiency is significantly higher in comparison with popular three−terminal linear regulators, especially with higher input voltages. In most cases, the power dissipated by the LM2574 regulator is so low, that the copper traces on the printed circuit board are normally the only heatsink needed and no additional heatsinking is required. The LM2574 features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency (±2% over 0°C to +125°C). External shutdown is included, featuring 60 μA (typical) standby current. The output switch in

The ADT7466 dBCool® Remote Thermal Controller and Voltage Monitor is a complete thermal monitor and dual fan controller for low acoustic noise notebook PCs. It features the ability to monitor two analog voltages or thermistor temperature inputs and control and monitor the speed of up to two fans. The controller also has an automatic fan speed control mode that controls system cooling based on measured temperature. It has a thermal protection feature via the THERM output that monitors the performance impact of the Intel® Pentium® 4 processor thermal control circuit via the PROCHOT input. It also includes an SMBus 1.1 serial interface and 3-wire fan speed measurement.

The NCP1337 combines a true current mode modulator and a demagnetization detector which ensures full Borderline/Critical Conduction Mode in any load/line conditions together with minimum drain voltage switching (Quasi−Resonant operation). The transformer core reset detection is done internally, without using any external signal, due to the Soxyless concept. The frequency is internally limited to 130 kHz, preventing the controller to operate above the 150 kHz CISPR−22 EMI starting limit. By monitoring the feedback pin activity, the controller enters ripple mode as soon as the power demand falls below a predetermined level. As each restart is softened by an internal soft−start, and as the frequency cannot go below 25 kHz, no audible noise can be heard. The NCP1337 also features an efficient protective circuitry which, in presence of an overcurrent condition, disables the output pulses and enters a safe burst mode, trying to restart. Once the default has gone, the device auto−recovers. Also included is a bulk voltage monitoring function (known as brown−out protection), an adjustable overpower compensation, and a VCC OVP. Finally, an internal 4.0 ms soft−start eliminates the traditional startup stress.

The MC14051B, MC14052B, and MC14053B are digitally-controlled analog multiplexers/demultiplexers. These devices feature low ON impedance and very low OFF leakage current. Control of analog signals up to the complete supply voltage range can be achieved.

The MC74HC4066A is a quad analog switch/multiplexer/demultiplexer that utilizes silicon-gate CMOS technology to achieve fast propagation delays, low ON resistances, and low OFF-channel leakage current. It can control analog and digital voltages that may vary across the full power-supply range (from VCC to GND). The device is identical in pinout to the metal-gate CMOS MC14016 and MC14066 and has four independent switches. The ON resistances (RON) of the device are more linear over input voltage than RON of metal-gate CMOS analog switches. The ON/OFF control inputs are compatible with standard CMOS outputs and, with pullup resistors, they are compatible with LSTTL outputs. For analog switches with voltage-level translators, see the HC4316A.

The MC14066B is a quad analog switch/quad multiplexer consisting of four independent switches capable of controlling either digital or analog signals. This quad bilateral switch is useful in signal gating, chopper, modulator, demodulator and CMOS logic implementation.

The NCP1400A series is a micropower step-up DC to DC converter designed specifically for powering portable equipment from one or two cell battery packs. These devices can start up with a voltage of 0.8V and operate down to as low as 0.2V. With only four external components, this series allows for the implementation of highly efficient converters capable of delivering up to 100mA of output current. Each device includes an on-chip fixed frequency oscillator, pulse width modulation controller, phase compensated error amplifier for stable operation in discontinuous mode, soft-start, voltage reference, driver, and power MOSFET switch with current limit protection. Additionally, there is a chip enable feature to power down the converter and extend battery life. The NCP1400A devices are available in the Thin SOT23-5 package with seven standard regulated output voltages. Additional voltages ranging from 1.8V to 4.9V in 100mV steps can be manufactured.

The P6KE6.8A series is designed to protect voltage sensitive components from high voltage, high energy transients. They have excellent clamping capability, high surge capability, low zener impedance and fast response time. These devices are ON Semiconductor's exclusive, cost-effective, highly reliable Surmetic� axial leaded package and is ideally-suited for use in communication systems, numerical controls, process controls, medical equipment, business machines, power supplies and many other industrial/consumer applications.

MC33501, MC33503 1.0 V, Rail−to−Rail, Single Operational Amplifiers The product is a single supply operational amplifier that provides rail−to−Rail operation on both the input and output, and the output voltage can swing within 50 mV of each power rail. It has high input impedance, high output current and low input offset

MC7800 is a 1.0A positive voltage regulator produced by Semiconductor Components Industries. It can be used in a variety of applications, including local, on-card regulation. These regulators employ internal current limiting, thermal shutdown, and safe-area compensation.

MC74HC4051A/D, MC74HC4052A, MC74HC4053A are high performance silicon-gate CMOS devices featuring fast propagation delays, low ON resistances, and low OFF leakage currents. These analog multiplexers/demultiplexers control analog voltages that may vary across the complete power supply range (from VCC to VEE). The HC4051A, HC4052A and HC4053A are identical in pinout to the metal-gate MC14051AB, MC14052AB and MC14053AB. The Channel-Select inputs determine which one of the Analog Inputs/Outputs is to be connected, by means of an analog switch, to the Common Output/Input. When the Enable pin is HIGH, all analog switches are turned off. The Channel-Select and Enable inputs are compatible with standard CMOS outputs; with pullup resistors they are compatible with LSTTL outputs. These devices have been designed so that the ON resistance (Ron) is more linear over input voltage than Ron of metal-gate CMOS analog switches. For a multiplexer/demultiplexer with injection current protection, see HC4851A and HC4852A.

MC34152/MC33152 are dual noninverting high speed drivers specifically designed for applications that require low current digital signals to drive large capacitive loads with high slew rates.

LM2576 3.0 A, 15 V, Step-Down Switching Regulator

This document introduces NCP101X series products. The series integrates a fixed frequency current mode controller and a 700 V MOSFET. It is housed in a PDIP-7, PDIP-7 Gull Wing, or SOT-223 package. It provides soft start, frequency jittering, short circuit protection, skip cycle, a maximum peak current setpoint and a Dynamic Self-Supply (no need for an auxiliary winding). The switching frequency is 65-100-130 kHz. When the current setpoint falls below a given value, e.g. the output power demand diminishes, the IC automatically enters the so-called skip-cycle mode and provides excellent efficiency at light loads. No acoustic noise takes place. Short-circuit detection takes place when the feedback signal fades away, e.g. in true short-circuit conditions or in broken Optocoupler cases. External disabling can be easily done either simply by pulling the feedback pin down or latching it to ground through an inexpensive SCR for complete latched-off.