IK3401 Datasheet, PDF (1/11 Pages) IK Semicon Co., Ltd – Green Mode PWM Controller

TECHNICAL DATA
Green Mode PWM Controller
Description
IK3401
The IK3401 is a green mode PWM controller. It is specially
designed for DVDP, STB and LCD monitor application.
To minimize standby power consumption, a green-mode
function provides off-time modulation to continuously
decrease the switching frequency at light-load conditions.
Under zero-load conditions, the power supply enters burst-
mode. To avoid acoustic noise problem, the minimum PWM frequency set above
20KHz. This green-mode function enables the power supply to easily meet international
power conservation requirements. To further reduce power consumption, IK3401 is
manufactured by using the HV-CMOS process. This allows the lowest start-up current
around 14uA, and the operating current is only 4mA. As a result, large start-up resistance
can be used.
The maximum power can be limited constantly, regardless of the line voltage change
using power limit function. The switching frequency is programmable or internally fixed to
be 65kHz.
IK3401 integrates frequency modulation technique internally. The frequency jittering
function helps reduce EMI emission of a power supply with minimum line filters. Also, its
built-in synchronized slope compensation achieves stable peak-current-mode control.
IK3401 provides many protection functions. In addition to cycle-by-cycle current limiting,
the internal open-loop protection circuit ensures safety should an open loop or output
short-circuit failure occurs. PWM output is disabled till VDD drops below the UVLO lower
limit. Then, the controller starts up again. As long as VDD exceeds about 24V, the internal
OVP circuit is triggered. For OVP and OTP, the protection mode can be chosen to be
latch off or auto recovery.
IK3401 is available in an 8-pin DIP or SOP package.
Features
· Green-mode PWM Control
· Low Start-Up Current (Typ. 14uA)
· Low Operating Current (Typ. 4mA)
· Programmable PWM frequency
with Frequency Jittering
· Peak-current-mode Control
· Cycle-by-Cycle Current Limiting
· Synchronized Slope Compensation
Applications
· Notebook Power Adapters
· DVD-P, STB, LCD Monitor Power
· Open-Frame SMPS
· Leading-Edge Blanking
· Constant Output Power Limit
· Totem Pole Output with Soft Driving
· VDD Over Voltage Protection (OVP)
· 150°C OTP with Hysteresis
· Internal Latch Circuit (OVP, OTP)
· Internal Open-loop Protection
· VDD Under-voltage Lockout (UVLO)
· GATE Output Maximum Voltage
Clamp (18V)
Rev 00