National Manuals

The LM4906 is a 1W audio power amplifier designed for mobile phones and other portable communication devices. It can deliver 1W of continuous average power to an 8Ω BTL load with less than 1% distortion from a +5V power supply. The LM4906 is the first National Semiconductor Boomer Power Amplifier that does not require an external PSRR bypass capacitor. It also has an internal selectable gain of either 6dB or 12dB. In addition, no output coupling capacitors or bootstrap capacitors are required, making it ideal for low voltage portable applications. The LM4906 features advanced pop and click circuitry to eliminate noise during turn-on and turn-off transitions. It has a low-power consumption shutdown mode and internal thermal shutdown protection mechanism.

LM2574/LM2574HV SIMPLE SWITCHER™ 0.5A Step-Down Voltage Regulator is a low-power buck converter from TI. It provides 3.3V, 5V, 12V, 15V and adjustable output voltages. It has a high efficiency and low standby current. It is suitable for various applications that need low power.

LM2662/LM2663 switched capacitor voltage converter inverts a positive voltage in the range of 1.5V to 5.5V to the corresponding negative voltage. The LM2662/LM2663 uses two low cost capacitors to provide 200 mA of output current without the cost, size, and EMI related to inductor based converters. With an operating current of only 300 µA and operating efficiency greater than 90% at most loads, the LM2662/LM2663 provides ideal performance for battery powered systems. The LM2662/LM2663 may also be used as a positive voltage doubler.

The LM2703 is a micropower step-up DC/DC in a small 5-lead SOT-23 package. A current limited, fixed off-time control scheme conserves operating current resulting in high efficiency over a wide range of load conditions. The 21V switch allows for output voltages as high as 20V. The low 400ns off-time permits the use of tiny, low profile inductors and capacitors to minimize footprint and cost space-conscious portable applications. The LM2703 is ideal for LCD panels requiring low current and high efficiency as well as white LED applications for cellular phone back-lighting. The LM2703 can drive up to 4 white LEDs from a single Li-Ion battery.

The LM2937 500 mA Low Dropout Regulator is a positive voltage regulator capable of supplying up to 500 mA of load current. Use of a PNP power transistor provides a low dropout voltage characteristic. With a load current of 500 mA the minimum input to output voltage differential required for the output to remain in regulation is typically 0.5V (1V guaranteed maximum over the full operating temperature range). Special circuitry has been incorporated to minimize the quiescent current to typically only 10 mA with a full 500 mA load current when the input to output voltage differential is greater than 3V. The LM2937 requires an output bypass capacitor for stability. As with most low dropout regulators, the ESR of this capacitor remains a critical design parameter, but the LM2937 includes special compensation circuitry that relaxes ESR requirements. The LM2937 is stable for all ESR below 3Ω. This allows the use of low ESR chip capacitors. Ideally suited for automotive applications, the LM2937 will protect itself and any load circuitry from reverse battery connections, two-battery jumps and up to +60V/−50V load dump transients. Familiar regulator features such as short circuit and thermal shutdown protection are also built in.

LM4836 is a stereo 2W audio power amplifier from Texas Instruments (TI). It integrates DC volume control, stereo bridge audio power amplifiers, selectable gain or bass boost, and an input mux.

The LM747 is a general purpose dual operational amplifier with features such as no frequency compensation required, short-circuit protection, wide common-mode and differential voltage ranges, low power consumption, and no latch-up.

The LM95221 is a digital temperature sensor produced by Texas Instruments. It uses the SMBus 2.0 interface and can detect three temperature zones, including its own temperature and the temperature of two diode connected transistors. The diode connected transistors can be a thermal diode as found in Pentium and AMD processors, or simply be a diode connected MMBT3904 transistor. The LM95221 remote temperature reading resolution format can be programmed to be 10-bits plus sign or 11-bits unsigned. In the unsigned mode, the LM95221 remote diode readings can resolve temperatures above 127 degrees Celsius. Local temperature readings have a resolution of 9-bits plus sign. Any ASIC can be accurately determined using the LM95221 as long as a dedicated diode (semiconductor junction) is available on the target die. The LM95221 remote sensor accuracy of ±1 degrees Celsius is factory trimmed for a series resistance of 2.7 ohms and a 1.008 non-ideality factor.

LMC7221 is a micropower CMOS comparator available in the space saving SOT23-5 package. This makes this comparator ideal for space and weight critical designs. The LMC7221 is also available in conventional DIP and SO-8 packages. The LMC7221 is supplied in two offset voltage grades, 5 mV and 15 mV. The open drain output can be pulled up with a resistor to a voltage which can be higher or lower than the supply voltage — this makes the part useful for mixed voltage systems. For a tiny comparator with a push-pull output, please see the LMC7211 datasheet.

The LMF90 is a fourth-order elliptic notch (band-reject) filter based on switched-capacitor techniques. No external components are needed to define the response function. The depth of the notch is set using a two-level logic input, and the width is programmed using a three-level logic input. Two different notch depths and three different ratios of notch width to center frequency may be programmed by connecting these pins to Va, ground, or Vb. Another three-level logic pin sets the ratio of clock frequency to notch frequency. An internal crystal oscillator is provided. Used in conjunction with a low-cost color TV crystal and the internal clock frequency divider, a notch filter can be built with center frequency at 50 Hz, 60 Hz, 100 Hz, 120 Hz, 150 Hz, or 180 Hz for rejection of power line interference. Several LMF90s can be operated from a single crystal. An additional input is provided for an externally-generated clock signal.

LMH6503 is a wideband, low power, linear variable gain amplifier with features such as wide gain adjustment range and low offset voltage.

LP2981 Micropower 100 mA Ultra Low-Dropout Regulator

The LP3961/LP3964 series of fast ultra low-dropout linear regulators operate from a +2.5V to +7.0V input supply. Wide range of preset output voltage options are available. These ultra low dropout linear regulators respond very fast to step changes in load which makes them suitable for low voltage microprocessor applications. The LP3961/LP3964 are de- veloped on a CMOS process which allows low quiescent current operation independent of output load current. This CMOS process also allows the LP3961/LP3964 to operate under extremely low dropout conditions.

The LP3985 is a micropower, 150mA low-noise ultra low-dropout CMOS voltage regulator that is designed for portable and wireless applications with demanding performance and space requirements. It has extremely low noise, extremely low dropout voltage and low quiescent current, making it ideal for battery powered systems. The LP3985 is stable with a small 1µF ±30% ceramic or high-quality tantalum output capacitor. The micro SMD size is extremely small, requiring the smallest possible PC board area. The total application circuit area can be less than 2.0mm x 2.5mm, which is only a fraction of a 1206 case size. An optional external bypass capacitor can be used to reduce output noise without slowing down the load transient response. Fast start-up time is achieved by using an internal power-on circuit that actively pre-charges the bypass capacitor. Power supply rejection is better than 50 dB at low frequencies and starts to roll off at 1kHz. High power supply rejection is maintained down to low input voltage levels common to battery operated circuits. The device is ideal for mobile phone and similar battery powered wireless applications. It provides up to 150 mA, from a 2.5V to 6V input. The LP3985 consumes less than 1.5µA in disable mode and has fast turn-on time less than 200µs. The LP3985 is available in a 5 bump small bump micro SMD, a 5 bump large bump micro SMD, and a 5 bump thin micro SMD package.

The 54AC378 is a 6-bit parallel D register with a buffered common Enable.