Microchip Technology

The MCP1012 is used as a primary-side start-up IC for starting an offline auxiliary switching supply working in conjunction with a secondary-side controller. The MCP1012 does not linearly regulate the power converter, but rather a secondary-side controller (digital and/or analog) accurately linear regulates using sophisticated adaptive control schemes that enhance performance and efficiency. The primary function of the MCP1012 are to provide startup of the flyback converter using an internal open-loop, peak current-mode current regulator. It does this by accepting PWM commands via an isolation medium (s.a. a pulse transformer, opto, or other) from a secondary-side controller. It integrates various protection features, including an undervoltage lockout (UVLO) and overvoltage lockout (OVLO) protection, and overtemperature protection (OTP.) Additionally, the MCP1012 provides peak cycle-by-cycle current limiting both when under control of its internal current regulator or under control of the secondary-side controller.

The MCP102 is a voltage supervisor device designed to keep a microcontroller in reset until the system voltage has reached and stabalized at the proper level for reliable system operation.

The MCP103 Series are CMOS voltage supervisors are well suited for many portable and consumer electrics applications due to the extremely low 1uA operating current and small surface-mount packaging. These devices are designed to hold the microcontroller in reset until the supply voltage reaches a predetermined operating level. These devices also protect against brownout conditions that occur as a result of the supply voltage dropping below a tolerable level.

The MCP111/112 Series are CMOS voltage detectors are well suited for portable, consumer electrics applications due to the extremely low 1uA operating current and small surface-mount packaging. These devices are designed to hold the microcontroller in reset until the supply voltage reaches a predetermined operating level. These devices also protect against brownout conditions that occur as a result of the supply voltage dropping below a tolerable level.

The MCP111/112 Series are CMOS voltage detectors are well suited for portable, consumer electrics applications due to the extremely low 1uA operating current and small surface-mount packaging. These devices are designed to hold the microcontroller in reset until the supply voltage reaches a predetermined operating level. These devices also protect against brownout conditions that occur as a result of the supply voltage dropping below a tolerable level.

The MCP120 is a voltage supervisory device designed to keep a microcontroller in reset until the system voltage has reached the proper level and stabilized. It also operates as protection from brown-out conditions when the supply voltage drops below a safe operating level. MCP120 features an open drain output, and active low reset and is available in a choice of seven different trip voltages. It operates over the extended industrial temperature range (-40°C/+85°C). MCP120 is available in a TO-92, SOT23-3, and SN packages.

The MCP121 Series of CMOS voltage detectors are well suited for many portable and consumer electrics applications due to the extremely low 1uA operating current and small surface-mount packaging. These devices are designed to hold the microcontroller in reset until the supply voltage reaches a predetermined operating level. These devices also protect against brownout conditions that occur as a result of the supply voltage dropping below a tolerable level.

The MCP1252-33X50 and MCP1252-ADJ are inductorless, positive regulating, low noise charge pump DC-to-DC converters. The MCP1252-33X50 has selectable outputs of either 3.3 or 5.0 V, while the MCP1252-ADJ has an adjustable output between 1.5 and 5.5 V. Both can deliver 120 mA of load current at the selected regulated output voltage. Since the device incorporates an automatic buck/boost feature, it will maintain the regulated output voltage whether the input voltage is above or below the output voltage. These charge pumps operateat a switching frequency of 650 kHz, and feature power saving shutdown pins, short circuit protection, thermal shutdown, and power-good pins that report out-of-regulation conditions.

The MCP1253-33X50 and MCP1253-ADJ are inductorless, positive regulating, low noise charge pump DC-to-DC converters. The MCP1253-33X50 has selectable outputs of either 3.3 or 5.0 V, while the MCP1253-ADJ has an adjustable output between 1.5 and 5.5 V. Both can deliver 120 mA of load current at the selected regulated output voltage. Since the device incorporates an automatic buck/boost feature, it will maintain the regulated output voltage whether the input voltage is above or below the output voltage. These charge pumps operateat a switching frequency of 1 MHz (reducing capacitor sizes), and feature power saving shutdown pins, short circuit protection, thermal shutdown, and power-good pins that report out-of-regulation conditions.

The MCP1256, MCP1257, MCP1258 and MCP1259 are inductorless, positive regulated charge pump DC/DC converters. Generating a regulated 3.3 V output voltage from a 1.8 V to 3.6 V input, they are specifically designed for applications operating from 2 cell alkaline, 2 cell Ni-Cd, 2 cell Ni-MH, or one primary lithium coin cell battery. These devices automatically switch from 1.5x to 2x boost operation modes to maintain high efficiency. In addition, at light output loads, the MCP1256 and MCP1257 can be placed in a sleep mode, lowering the quiescent current while maintaining the regulated output voltage. Alternatively, the MCP1258 and MCP1259 provide a bypass feature connecting the input voltage to the output. This allows for real-time clocks, microcontrollers or other system devices to remain biased with virtually no current being consumed by the MCP1258 or MPC1259. In normal operation, the charge pumps switch at a fixed 650 kHz, avoiding sensitive IF bands, and the output voltage ripple is below 20 mVP-P at load currents up to 100 mA. The MCP1256 and MCP1258 feature a power-good output that can be used to detect out-of-regulation conditions. The MCP1257 and MCP1259 feature a low battery indication that issues a warning if the input voltage drops below a preset voltage threshold. Extremely low supply current and few external parts (4 capacitors) make these devices ideal for small, battery powered applications. A shutdown mode is also provided for further power reduction. The devices incorporate thermal and short-circuit protection.