Datasheet ADUM3070 (Analog Devices) - 8

ADuM3070 Data Sheet PIN CONFIGURATION AND FUNCTION DESCRIPTIONS X1 1 16 VREG *GND 2 15 1 GND2* NC 3 ADuM3070 14 VDD2 TOP VIEW X2 4 13 FB (Not to Scale) TP 5 12 NC TP 6 11 NC V 7 10 DDA OC 8 9 *GND1 GND2* *PIN 2 AND PIN 8 ARE INTERNALLY CONNECTED, AND CONNECTING BOTH TO GND1 IS RECOMMENDED. PIN 9 AND PIN 15 ARE INTERNALLY CONNECTED, AND CONNECTING BOTH TO GND2 IS RECOMMENDED. NOTES
003
1. NC = NO CONNECT. DO NOT CONNECT TO THIS PIN. 2. TP = TEST POINT. DO NOT CONNECT TO THIS PIN.
10437- Figure 3. Pin Configuration See Application Note AN-1109 for specific layout guidelines.
Table 12. Pin Function Descriptions Pin No. Mnemonic Description
1 X1 Transformer Driver Output 1. 2, 8 GND1 Ground Reference for Primary Side. 3, 11, 12 NC No Connect. Do not connect to this pin. 5, 6 TP Test Point. Do not connect to this pin. 4 X2 Transformer Driver Output 2. 7 VDDA Primary Supply Voltage 3.0 V to 5.5 V. Connect to VDD1. Connect a 0.1 µF bypass capacitor from VDDA to GND1. 9, 15 GND2 Ground Reference for Secondary Side. 10 OC Oscillator Control Pin. When OC = logic high = VDD2, the secondary controller runs open-loop. To regulate the output voltage, connect a resistor between the OC pin and GND2, and the secondary controller runs at a frequency of 200 kHz to 1 MHz, as programmed by the resistor value. 13 FB Feedback Input from the Secondary Output Voltage VISO. Use a resistor divider from VISO to the FB pin to make the VFB voltage equal to the 1.25 V internal reference level using the VISO = VFB × (R1 + R2)/R2 formula. The resistor divider is required even in open-loop mode to provide soft start. 14 VDD2 Internal Supply Voltage Pin for the Secondary Side Controller. When a sufficient external voltage is supplied to VREG, the internal regulator regulates the VDD2 pin to 5.0 V. Otherwise, VDD2 should be in the 3.0 V to 5.5 V range. Connect a 0.1 µF bypass capacitor from VDD2 to GND2. 16 VREG Input of the Internal Regulator to Power the Secondary Side Controller. VREG should be in the 5.5 V to 15 V range to regulate the VDD2 output to 5.0 V. Rev. A | Page 8 of 20 Document Outline Features Applications Functional Block Diagram General Description Table of Contents Revision History Specifications Electrical Characteristics—5 V Primary Input Supply/5 V Secondary Isolated Supply Electrical Characteristics—3.3 V Primary Input Supply/3.3 V Secondary Isolated Supply Electrical Characteristics—5 V Primary Input Supply/3.3 V Secondary Isolated Supply Electrical Characteristics—5 V Primary Input Supply/15 V Secondary Isolated Supply Package Characteristics Regulatory Approvals (Pending) Insulation and Safety Related Specifications DIN V VDE V 0884-10 (VDE V 0884-10) Insulation Characteristics Recommended Operating Conditions Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Applications Information Application Schematics Transformer Design Transformer Turns Ratio Transformer ET Constant Transformer Primary Inductance and Resistance Transformer Isolation Voltage Switching Frequency Transient Response Component Selection Printed Circuit Board (PCB) Layout Thermal Analysis Power Consumption Power Considerations Soft Start Mode and Current-Limit Protection Insulation Lifetime Outline Dimensions Ordering Guide