Texas Instruments

The LM34966-Q1 is a wide input range, non-synchronous boost controller that uses peak current mode control. The device can be used in boost, SEPIC, and flyback topologies. The device can start up from a 1-cell battery with a minimum of 2.97 V if the BIAS pin is connected to the VCC pin. It can operate with the input supply voltage as low as 1.5 V if the BIAS pin is greater than 3.5 V. The internal VCC regulator also supports BIAS pin operation up to 40 V (45-V absolute maximum) for automotive load dump. The switching frequency is dynamically programmable with an external resistor from 100 kHz to 500 kHz. The LM34966-Q1 is a wide input range, non-synchronous boost controller that uses peak current mode control. The device can be used in boost, SEPIC, and flyback topologies. The device can start up from a 1-cell battery with a minimum of 2.97 V if the BIAS pin is connected to the VCC pin. It can operate with the input supply voltage as low as 1.5 V if the BIAS pin is greater than 3.5 V. The internal VCC regulator also supports BIAS pin operation up to 40 V (45-V absolute maximum) for automotive load dump. The switching frequency is dynamically programmable with an external resistor from 100 kHz to 500 kHz.

The LM150 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 3A over a 1.2V to 33V output range. They are exceptionally easy to use and require only 2 external resistors to set the output voltage. Further, both line and load regulation are comparable to discrete designs. Also, the LM150 is packaged in standard transistor packages which are easily mounted and handled. In addition to higher performance than fixed regulators, the LM150 series offers full overload protection available only in IC's. Included on the chip are current limit, thermal overload protection and safe area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is accidentally disconnected. Normally, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors in which case an input bypass is needed. An output capacitor can be added to improve transient response, while bypassing the adjustment pin will increase the regulator's ripple rejection. Besides replacing fixed regulators or discrete designs, the LM150 is useful in a wide variety of other applications. Since the regulator is "floating" and sees only the input-to-output differential voltage, supplies of several hundred volts can be regulated as long as the maximum input to output differential is not exceeded, i.e., avoid short-circuiting the output. By connecting a fixed resistor between the adjustment pin and output, the LM150 can be used as a precision current regulator. Supplies with electronic shutdown can be achieved by clamping the adjustment terminal to ground which programs the output to 1.2V where most loads draw little current. The part numbers in the LM150 series which have a NDS suffix are packaged in a standard Steel TO-3 package, while those with a NDE suffix are packaged in a TO-220 plastic package. The LM150 is rated for −55°C ≤ TJ≤ +150°C, while the LM350A is rated for −40°C ≤ TJ≤ +125°C, and the LM350 is rated for 0°C ≤ TJ≤ +125°C. The LM150 series of adjustable 3-terminal positive voltage regulators is capable of supplying in excess of 3A over a 1.2V to 33V output range. They are exceptionally easy to use and require only 2 external resistors to set the output voltage. Further, both line and load regulation are comparable to discrete designs. Also, the LM150 is packaged in standard transistor packages which are easily mounted and handled. In addition to higher performance than fixed regulators, the LM150 series offers full overload protection available only in IC's. Included on the chip are current limit, thermal overload protection and safe area protection. All overload protection circuitry remains fully functional even if the adjustment terminal is accidentally disconnected. Normally, no capacitors are needed unless the device is situated more than 6 inches from the input filter capacitors in which case an input bypass is needed. An output capacitor can be added to improve transient response, while bypassing the adjustment pin will increase the regulator's ripple rejection. Besides replacing fixed regulators or discrete designs, the LM150 is useful in a wide variety of other applications. Since the regulator is "floating" and sees only the input-to-output differential voltage, supplies of several hundred volts can be regulated as long as the maximum input to output differential is not exceeded, i.e., avoid short-circuiting the output. By connecting a fixed resistor between the adjustment pin and output, the LM150 can be used as a precision current regulator. Supplies with electronic shutdown can be achieved by clamping the adjustment terminal to ground which programs the output to 1.2V where most loads draw little current. The part numbers in the LM150 series which have a NDS suffix are packaged in a standard Steel TO-3 package, while those with a NDE suffix are packaged in a TO-220 plastic package. The LM150 is rated for −55°C ≤ TJ≤ +150°C, while the LM350A is rated for −40°C ≤ TJ≤ +125°C, and the LM350 is rated for 0°C ≤ TJ≤ +125°C.

The LM3501 is a fixed-frequency step-up DC/DC converter that is ideal for driving white LEDs for display backlighting and other lighting functions. With fully integrated synchronous switching (no external schottky diode required) and a low feedback voltage (515 mV), power efficiency of the LM3501 circuit has been optimized for lighting applications in wireless phones and other portable products (single cell Li-Ion or 3-cell NiMH battery supplies). The LM3501 operates with a fixed 1 MHz switching frequency. When used with ceramic input and output capacitors, the LM3501 provides a small, low-noise, low-cost solution. Two LM3501 options are available with different output voltage capabilities. The LM3501-21 has a maximum output voltage of 21V and is typically suited for driving 4 or 5 white LEDs in series. The LM3501-16 has a maximum output voltage of 16V and is typically suited for driving 3 or 4 white LEDs in series (maximum number of series LEDs dependent on LED forward voltage). If the primary white LED network should be disconnected, the LM3501 uses internal protection circuitry on the output to prevent a destructive overvoltage event. A single external resistor is used to set the maximum LED current in LED-drive applications. The LED current can easily be adjusted by varying the analog control voltage on the control pin or by using a pulse width modulated (PWM) signal on the shutdown pin. In shutdown, the LM3501 completely disconnects the input from output, creating total isolation and preventing any leakage currents from trickling into the LEDs. The LM3501 is a fixed-frequency step-up DC/DC converter that is ideal for driving white LEDs for display backlighting and other lighting functions. With fully integrated synchronous switching (no external schottky diode required) and a low feedback voltage (515 mV), power efficiency of the LM3501 circuit has been optimized for lighting applications in wireless phones and other portable products (single cell Li-Ion or 3-cell NiMH battery supplies). The LM3501 operates with a fixed 1 MHz switching frequency. When used with ceramic input and output capacitors, the LM3501 provides a small, low-noise, low-cost solution. Two LM3501 options are available with different output voltage capabilities. The LM3501-21 has a maximum output voltage of 21V and is typically suited for driving 4 or 5 white LEDs in series. The LM3501-16 has a maximum output voltage of 16V and is typically suited for driving 3 or 4 white LEDs in series (maximum number of series LEDs dependent on LED forward voltage). If the primary white LED network should be disconnected, the LM3501 uses internal protection circuitry on the output to prevent a destructive overvoltage event. A single external resistor is used to set the maximum LED current in LED-drive applications. The LED current can easily be adjusted by varying the analog control voltage on the control pin or by using a pulse width modulated (PWM) signal on the shutdown pin. In shutdown, the LM3501 completely disconnects the input from output, creating total isolation and preventing any leakage currents from trickling into the LEDs.

The LM3508 is a synchronous boost converter (no external Schottky diode required) that provides a constant current output. It is designed to drive up to 4 series white LEDs at 30mA from a single-cell Li-Ion battery. A single low power external resistor is used to set the maximum LED current. The LED current can be adjusted by applying a PWM signal of up to 100kHz to the DIM pin. Internal soft-start circuitry is designed to eliminate high in-rush current at start-up. For maximum safety, the device features an advanced short-circuit protection when the output is shorted to ground. Additionally, over-voltage protection and an 850kHz switching frequency allow for the use of small, low-cost output capacitors with lower voltage ratings. During shutdown, the output is disconnected from the input preventing a leakage current path through the LEDs to ground. The LM3508 is available in a tiny 9-bump chip-scale DSBGA package. The LM3508 is a synchronous boost converter (no external Schottky diode required) that provides a constant current output. It is designed to drive up to 4 series white LEDs at 30mA from a single-cell Li-Ion battery. A single low power external resistor is used to set the maximum LED current. The LED current can be adjusted by applying a PWM signal of up to 100kHz to the DIM pin. Internal soft-start circuitry is designed to eliminate high in-rush current at start-up. For maximum safety, the device features an advanced short-circuit protection when the output is shorted to ground. Additionally, over-voltage protection and an 850kHz switching frequency allow for the use of small, low-cost output capacitors with lower voltage ratings. During shutdown, the output is disconnected from the input preventing a leakage current path through the LEDs to ground. The LM3508 is available in a tiny 9-bump chip-scale DSBGA package.