IK3301
Electrical Description
The standard external components for standard load are shown in Figure 4.
1. Multi-output Generation(-8V & 5V & 15V)
IK3301 consists of CMOS step-down, step-up, and Voltage-inverting switching regulator, which produces
5V, 15V, and -8V. This device contains an internal temperature compensated bandgap reference,
comparator, duty cycle controlled oscillator with cycle-cycle current limit circuit, and high current
output switch with logic gates. Three outputs of 5V, 15V, and -8V are adjustable through two
external feedback resistors with 2% reference voltage accuracy. The power efficiency depends on
the value and the efficiency of external components, the load current and the target ripple voltage.
The minimum efficiency of the 5V voltage generator is 80% with the reference circuit shown in
Figure 4. The maximum load current of 5V of the reference circuit is 300mA, the maximum ripple
voltage is 20mV. To save external components, internal Pch and Nch Power MOS FET are used
to generate -8V and 15V. The 5V Pch Power MOS FET is used as external component because of
high peak current and package power dissipation.
2. Internal BG Reference
IK3301 generates three outputs which are determined by the internal bandgap reference voltage and the
ratio of the feedback resistors. Therefore, the output voltages of 15V, 5V, and -8V are also
insensitive of the temperature and power supply variations.
3. Internal Oscillator
IK3301 has an internal oscillator which charges and discharges the internal timing capacitor using current
sourcing and sinking between an upper and lower predetermined threshold voltage. The upper
threshold voltage is 1.8V and the lower threshold voltage is 0.8V. The charging current and
discharging current ratio is one to six which will vary depending on running frequency. The
oscillator frequency is around 500KHz which is determined by the chosen internal capacitor value
and charging & discharging current and oscillator amplitude.
Internal Oscillator
2011, February, Rev. 02
5
Rev. 01
IKSEMICON [ IK SEMICON CO., LTD ]
