Datasheet InnoSwitch-CP (Power Integrations) - 9

InnoSwitch-CP
not on for the full switching cycle, a small low current diode is still
Key Application Considerations
required (D3) for best in class efficiency.
Output Power Table
The secondary-side of the IC is self-powered from either the The data sheet output power table (Table 1) represents the minimum secondary winding forward voltage or the output voltage. Capacitor practical continuous output power level that can be obtained under C12 connected to the BPS pin of the InnoSwitch-CP IC U1, provides the fol owing assumed conditions: decoupling for the internal circuitry. 1. The minimum DC input voltage is 90 V or higher for 85 VAC input, During CC operation, when the output voltage fal s, the device will or 220 V or higher for 230 VAC input or 115 VAC with a voltage power itself from the secondary winding directly. During the on-time doubler. The value of the input capacitance should be sized to of the primary-side power MOSFET, the forward voltage that appears meet these criteria for AC input designs. across the secondary winding is used to charge the decoupling 2. Efficiency of >82%. capacitor C12 via resistor R7 and an internal regulator. This al ows 3. Minimum data sheet value of I2f. output current regulation to be maintained down to ~3 V. Below this 4. Transformer primary inductance tolerance of ±10%. level the unit enters auto- restart until the output load is reduced. 5. Reflected output voltage (V ) of 110 V. OR Output current is sensed between the IS and GND pins with a 6. Voltage only output of 12 V with a synchronous rectifier. threshold of approximately 33 mV to reduce losses. Once the current 7. Increased current limit is selected for peak and open frame power sense threshold is exceeded the device adjusts the number of switch columns and standard current limit for adapter columns. pulses to maintain a fixed output current. During a fault condition 8. The part is board mounted with SOURCE pins soldered to a such as short-circuit of output, a large current will flow through the sufficient area of copper and/or a heat sink is used to keep the current sense resistors R13 due to discharge of the output capacitors SOURCE pin temperature at or below 110 °C. C10 and C11 through the short-circuit. 9. Ambient temperature of 50 °C for open frame designs and 40 °C for sealed adapters. The output voltage is sensed via resistor divider R9 and R10. Output voltage is regulated so as to achieve a voltage of 1.265 V on the *Below a value of 1, K is the ratio of ripple to peak primary current. P FEEDBACK pin. Capacitor C13 provides noise filtering of the signal at To prevent reduced power delivery, due to premature termination of the FEEDBACK pin. switching cycles, a transient K limit of ≥0.25 is recommended. This P prevents the initial current limit (I ) from being exceeded at INIT MOSFET turn-on.
Overvoltage Protection VOUT
The output overvoltage protection provided by the InnoSwitch-CP IC uses an internal latch that is triggered by a threshold current of RC approximately 7.6 mA into the PRIMARY BYPASS pin. In addition to RA an internal filter, the PRIMARY BYPASS pin capacitor forms an external CA filter providing noise immunity from inadvertent triggering. For the CB bypass capacitor to be effective as a high frequency filter, the capacitor should be located as close as possible to the SOURCE and RB PRIMARY BYPASS pins of the device. The primary sensed OVP function can be realized by connecting
InnoSwitch
a Zener diode from the rectified and filtered bias winding voltage
GND FB
supply to the PRIMARY BYPASS pin (paral el to R4 in Figure 15). Selecting the Zener diode voltage to be approximately 6 V above the bias winding voltage (28 V for 22 V bias winding) gives good OVP performance for most designs, but can be adjusted to compensate
IS
for variations in leakage inductance. Adding additional filtering can be achieved by inserting a low value (10 W to 47 W) resistor in series
RTN
with the bias winding diode and/or the OVP Zener diode. The resistor in series with the OVP Zener diode also limits the maximum current PI-8443-092717 into the BYPASS pin.
Reducing No-load Consumption
Figure 16. Feedback Network. The InnoSwitch-CP IC can start in self-powered mode from the BYPASS pin capacitor charged through the internal current source. Better load regulation and lower output ripple can be achieved by Use of a bias winding is however required to provide supply current to matching the time constants of upper and lower feedback divider the PRIMARY BYPASS pin once the InnoSwitch-CP IC has become network. As shown in Figure 16. operational. Auxiliary or bias winding provided on the transformer is required for this purpose. The addition of a bias winding that provides RB CB , RA CA bias supply to the PRIMARY BYPASS pin enables design of power The CHY103 interface IC provides QC 3.0 and QC 2.0 interface. supplies with no-load power consumption down to <30 mW. Resistor Resistor R11 provides supply current to the IC U2 and capacitor C14 R4 shown in Figure 15 should be adjusted to achieve the lowest provides decoupling. IC U2 increases or decreases the output voltage no-load input power. of the charger by either injecting or sinking current from the potential divider formed by resistors R9 or R10.
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Rev. F 09/17 www.power.com Document Outline Product Highlights Highly Integrated, Compact Footprint EcoSmart - Energy Efficient Advanced Protection / Safety Features Full Safety and Regulatory Compliance Green Package Applications Description Output Power Table Pin Functional Description InnoSwitch-CP Functional Description InnoSwitch-CP Operation Applications Example Key application Considerations Selection of Components Recommendations for Circuit Board Layout Recommendations for EMI Reduction Recommendations for Audible Noise Suppression Recommendations for Transformer Design Quick Design Checklist Absolute Maximum Ratings Thermal Resistance Key Electrical Characteristics NOTES Typical Performance Characteristics eSOP-R16B Package Package Marking MSL Table ESD and Latch-Up Table Part Ordering Information