General Description
The AP3154 is a high efficiency charge-pump white LED driver with 1x, 1.5x, 2x operating modes. The AP3154 operates on power supplies from 2.7v to 5.5v. It drives up to four channels of white LEDs while the intensity of each channel is configured by varying the respective current levels. Each channel can supply up to 30mA current. Up to four channels can be ganged together to provide maximum load current of 120mA.
The Serial Digital Interface (SDI) provides the capability to configure the current for each LED channel. Some other key features, such as Up Spread Spectrum Control, different charge-pump switching frequencies (0.6MHz/1.2MHz/1.8MHz), and PWM dimming control, can also be programmed through the interface.
The AP3154 has a built-in soft-start circuit to minimize the inrush current during power-up and mode switching. Various protections such as short-circuit, over-voltage, under-voltage, and thermal shutdown are integrated to ensure system reliability. The quiescent current of AP3154 during shutdown is less than 6μA.

*Up to 88% Max power efficiency
*Wide input voltage range: 2.7V ~ 5.5V
*1x, 1.5x, and 2x charge-pump modes
*Drive up to 4 white LEDs
*Default maximum current setting: 30mA each channel
*120mA maximum output current through 4 channels
*Programmable switching frequency, default 1.2MHz
*Spread Spectrum Control with 10% frequency deviation
*1-wire Serial Digital Interface (SDI) or PWM for dimming control
*Soft-start during power-up and mode switching
*Soft-stop during shutdown
*Short-circuit protection
*Over-voltage protection and under-voltage lockout
*Low shutdown current < 6μA
*Industry-leading low profile package
*DFN3030-12: Available in “Green” Molding Compound (No Br, Sb)
*Lead Free Finish / RoHS Compliant (Note 1)

*Mobile Phone
*PDA (Personal Digital Assistant)
*White LED Backlighting
*Camera Flash LED Lighting
*LCD Modules
*Portable Devices


댓글을 달아 주세요 Comment

The SSM2335 is a fully integrated, high efficiency, Class-D audio amplifier. It is designed to maximize performance for mobile phone applications. The application circuit requires a minimum of external components and operates from a single 2.5 V to 5.5 V supply. It is capable of delivering 3 W of continuous output power with <1% THD + N driving a 3 Ω load from a 5.0 V supply.
The SSM2335 features a high efficiency, low noise modulation scheme that requires no external LC output filters. The modu-lation continues to provide high efficiency even at low output power. It operates with 93% efficiency at 1.4 W into 8 Ω or 85% efficiency at 3 W into 3 Ω from a 5.0 V supply and has an SNR of >96 dB. Spread-spectrum pulse density modulation is used to provide lower EMI-radiated emissions compared with other Class-D architectures.
The SSM2335 has a micropower shutdown mode with a typical shutdown current of 20 nA. Shutdown is enabled by applying a logic low to the SD pin.
The device also includes pop-and-click suppression circuitry. This suppression circuitry minimizes voltage glitches at the output during turn-on and turn-off, reducing audible noise on activation and deactivation.
The fully differential input of the SSM2335 provides excellent rejection of common-mode noise on the input. Input coupling capacitors can be omitted if the input dc common-mode voltage is approximately VDD/2.
The default gain of the SSM2335 is 18 dB, but users can reduce the gain by using a pair of external resistors (see the Gain section).
The SSM2335 is specified over the industrial temperature range of −40°C to +85°C. It has built-in thermal shutdown and output short-circuit protection. It is available in a 9-ball, 1.5 mm × 1.5 mm wafer level chip scale package (WLCSP).

*Filterless Class-D amplifier with Σ-Δ modulation
*No sync necessary when using multiple Class-D amplifiers from Analog Devices, Inc.
*3 W into 3 Ω load and 1.4 W into 8 Ω load at 5.0 V supply with <1% total harmonic distortion (THD + N)
*93% efficiency at 5.0 V, 1.4 W into 8 Ω speaker
*>96 dB signal-to-noise ratio (SNR)
*Single-supply operation from 2.5 V to 5.5 V
*20 nA ultralow shutdown current
*Short-circuit and thermal protection
*Available in 9-ball, 1.5 mm × 1.5 mm WLCSP
*Pop-and-click suppression
*Built-in resistors reduce board component count
*Default fixed 18 dB or user-adjustable gain setting

Mobile phones
MP3 players
Portable gaming
Portable electronics
Educational toys


댓글을 달아 주세요 Comment

The ACT6357 and ACT6358 step-up DC/DC converters drive white LEDs with an externally programmable constant current.
These devices feature integrated, 40V power MOSFETs that are capable of driving up to ten white LEDs in series, providing inherent current matching for uniform brightness.
WLED brightness adjustment is easily achieved via a dual-function pin, which accepts either a PWM or an analog dimming control signal.
The ACT6357 and ACT6358 feature a variety of protection circuits, including integrated over voltage protection (OVP), programmable soft-start, cycleby- cycle current limiting, and thermal shutdown protection circuitry.
The ACT6357 has 500mA current limit, while the ACT6358 has 1A current limit.
Both parts are available in a small 3mm x 3mm 8-pin TDFN33-8.

* High-Efficiency DC/DC WLED Bias Supply
* Internal 40V, 0.55Ω Power MOSFET
* Up to 10 WLEDs per String
* Two Peak Current Options:
-ACT6357: 0.5A
-ACT6358: 1A
* Supports Analog and PWM LED Dimming
* Integrated Over-Voltage Protection (OVP)
* Programmable Soft-Start Function
* Thermal Shutdown
* Cycle-by-Cycle Over Current Protection
* Tiny TDFN33-8 Package

* TFT LCD Displays
* Smart Phones
* Portable Media Players
* GPS/Personal Navigation Devices


댓글을 달아 주세요 Comment