Micrel Manuals

The MIC2168 is a high-efficiency, simple to use 1MHz PWM synchronous buck control IC housed in a small MSOP-10 package. The MIC2168 allows compact DC/DC solutions with a minimal external component count and cost. The MIC2168 operates from a 3V to 14.5V input, without the need of any additional bias voltage. The output voltage can be precisely regulated down to 0.8V. The adaptive all N-Channel MOSFET drive scheme allows efficiencies over 95% across a wide load range. The MIC2168 senses current across the high-side N-Chan- Nel MOSFET, eliminating the need for an expensive and lossy current-sense resistor. Current limit accuracy is main- tained by a positive temperature coefficient that tracks the increasing RDS(ON) of the external MOSFET. Further cost and space are saved by the internal in-rush-current limiting digital soft-start. The MIC2168 is available in a 10-pin MSOP package, with a wide junction operating range of –40°C to +125°C. All support documentation can be found on Micrel’s web site at www.micrel.com.

The MIC2145 is a high efficiency 2.5W boost converter from Micrel. It is suitable for applications with single-cell Li-Ion batteries and 3-4 cell alkaline/NiCad/NiMH batteries. The MIC2145 supports an input voltage range of 2.4V to 16V and can output up to 16V. The chip operates at 450kHz and supports small external components. It has low static current and high efficiency.

The MIC2142 is a micropower boost switching regulator suitable for one-cell Li Ion and 3 to 4-cell alkaline/NiCad/NiMH applications. It features low quiescent current, adjustable output voltage, and is well suited for portable, space-sensitive applications.

The MIC2141 is a micropower boost switching regulator that can operate from 3- or 4-cell nickel-metal-hydride batteries or a single Li-ion cell. This regulator employs a constant 330kHz, fixed 18% duty-cycle, gated-oscillator architecture. The MIC2141 can be used in applications where the output voltage must be dynamically adjusted. The device features a control signal input which is used to proportionally adjust the output voltage. The control signal input has a gain of 6, allowing a 0.8V to 3.6V control signal to vary a 4.8V to 22V output. The MIC2141 requires only three external components to operate and is available in a tiny 5-lead SOT-23 package for space and power-sensitive portable applications. The MIC2141 draws only 70µA of quiescent current and can operate with an efficiency exceeding 85%.

The MIC2085/2086 are single channel positive voltage hot swap controllers designed to allow the safe insertion of boards into live system backplanes.

This document introduces the MIC2027/2077 quad USB power distribution switch, which features overcurrent protection and thermal shutdown, and has an integrated soft-start circuit to minimize inrush current in applications with highly capacitive loads. The switch also provides a fault status output signal to indicate overcurrent and thermal shutdown conditions.

This document introduces the features and characteristics of the MIC2026/2076 dual-channel power distribution switch.

The MIC2025 and MIC2075 are high-side MOSFET switches optimized for general-purpose power distribution requiring circuit protection. The MIC2025/75 are internally current limited and have thermal shutdown that protects the device and load. The MIC2075 offers “smart” thermal shutdown that reduces current consumption in fault modes. When a thermal shutdown fault occurs, the output is latched off until the faulty load is removed. Removing the load or toggling the enable input will reset the device output. Both devices employ soft-start circuitry that minimizes inrush current in applications where highly capacitive loads are employed. A fault status output flag is provided that is asserted during overcurrent and thermal shutdown conditions. The MIC2025/75 is available in the MM8™ 8-lead MSOP and 8-lead SOP.

This document introduces the characteristics and features of Micrel MIC184 Local/Remote Thermal Supervisor, including measuring local and remote temperatures, compatibility with LM75, 9-bit sigma-delta ADC, 2-wire I2C/SMBus compatible interface, programmable temperature settings, etc.

Micrel MIC2003/2013 are high-side current limiting devices, designed for power distribution applications in PCs, PDAs, printers and peripheral devices.

The MIC1832 is a multifunction circuit which monitors microprocessor activity, external reset and power supplies in microprocessor based systems. The circuit functions include a watchdog timer, power supply monitor, microprocessor reset, and manual pushbutton reset input. The power supply line is monitored with a comparator and an internal voltage reference. RST is forced low when an out-of-tolerance condition exists and remains asserted for at least 250ms after VCC rises above the threshold voltage (2.55V or 2.88V). The RST pin will remain logic low with VCC as low as 1.4V. The Watchdog input (ST) monitors µP activity and will assert RST if no µP activity has occurred within the watchdog timeout period. The watchdog timeout period is selectable with a nominal periods of 150, 600, or 1200 milliseconds.

The MIC1815 is a Microprocessor Reset Circuit from Micrel, it monitors the power supply in microprocessor based systems and generates a reset signal when the supply voltage drops below a pre-determined reset threshold voltage. There are a number of different reset threshold voltages available to accommodate 10% or 20% drop in 3.3V powered systems. The MIC1815 has a low-level RESET output. The reset output is guaranteed to remain asserted for a minimum of 100ms after VCC has risen above the designated reset threshold level. The MIC1815 is available in a 3-lead SOT-23 package.

The MIC1810 is an inexpensive microprocessor supervisory circuit that monitors power supplies in microprocessor-based systems. The function of these devices is to assert a reset if the power supply drops below a designated reset threshold level. Several different reset threshold levels are available to accommodate a 5%, 10%, or 15% drop in 5V powered systems. The MIC1810 has an active low RESET output. The reset output is guaranteed to remain asserted for a minimum of 100ms after VCC has risen above the designated reset threshold level. The MIC1810 comes in a 3-pin SOT-23 package.

The MIC1232 is a multifunction circuit which monitors microprocessor activity, external reset and power supplies in microprocessor based systems. The circuit functions include a watchdog timer, power supply monitor, microprocessor reset, and manual pushbutton reset input. The power supply line is monitored with a comparator and an internal voltage reference. RST is forced low when an out-of-tolerance condition exists and remains asserted for at least 250ms after VCC rises above the threshold voltage (4.5V or 4.75V). The RST pin will remain logic low with VCC as low as 1.4V. The Watchdog input (ST) monitors µP activity and will assert RST if no µP activity has occurred within the watchdog timeout period. The watchdog timeout period is selectable with nominal periods of 150, 600, or 1200 milliseconds.

micrel's two display controller chips, can drive vacuum fluorescent or LED displays