1.2.1

Peripheral Devices

The following is the list of PD70210/A/AL peripheral devices.

• Place 47 nF to 100 nF/100 V capacitor between the device's VPP and VPNI pins and close to the device.

• Place a 58 V TVS between device VPP and VPN_IN pins for protection against voltage transients. For complete

surge protection, see AN3410 Design for PD System Surge Immunity PD701xx and PD702xx Application Note.

• If 4-pair flags are used, place a 10 KΩ resistor on SUPP_S1 and SUPP_S2 lines between the diode bridge and

PD70210/A device.

• When WA_EN is used, place 100 nF to 1 μF/10 V capacitor between WA_EN and the VPN_IN pin, close to the

PD70210/A device.

• When it is not used, connect the WA_EN to the VPN_IN pin.

• Place 4.7 μF/25 V capacitor between Vaux pin and VPN_OUT.

1.2.2

Operation with an External DC Source

PD applications using PD70210A IC operates with an external power source (DC wall adapter). The two cases of

providing power with an external source is detailed in the following sections.

1.2.2.1

External Power Input Connected to Application Supply Rails

In this application, the external source is connected to the application’s low-voltage supply rails. The external source

voltage level depends on DC–DC output characteristics.

Figure 1-3. External Power Input to Supply Rails

100 nF

100 V

Primary DC (+)

Bootstrap Winding

Controller VCC

Primary DC (–)

Isolated Output

Isolated Output

Isolated DCDC

Application

PD70210A

VAUX

Vpp

WA_EN

AT_FLAG

VPNo

VPNo

Supp_S1

Rdet

Rcls

VPNI

VPNI

Supp_S2

Rref

HD_FLAG

4P_AT_FLG

4P_HD_FLG

SUPP_S1

SUPP_S2

(–) Input

(+) Input

Data– from

line XFMR

Data+ from

line XFMR

Spare+ from

line XFMR

Spare– from

line XFMR

10K

10K

SUPP_S1

SUPP_S2

100 nF

100 nF

1.2.2.2

External Power Input Connected to PD70210A Output

In this application, the external source is connected to the PD device's output connection for the application (VPP to

Figure 1-4. External Power Input to PD70210A Output

100 nF

100 V

Primary DC (+)

Bootstrap Winding

Controller VCC

Primary DC (–)

Isolated Output

Isolated Output

Isolated DCDC

Application

PD70210A

VAUX

Vpp

WA_EN

AT_FLAG

VPNo

VPNo

Supp_S1

Rdet

Rcls

VPNI

VPNI

Supp_S2

Rref

HD_FLAG

4P_AT_FLG

4P_HD_FLG

SUPP_S1

SUPP_S2

–

SUPP_S2

IN1B

IN2B

OUTN

+

SUPP_S1

OUTP

IN1A

IN2A

–

SUPP_S2

IN1B

IN2B

OUTN

+

SUPP_S1

OUTP

IN1A

IN2A

Data– from

line XFMR

Data+ from

line XFMR

Spare+ from

line XFMR

Spare– from

line XFMR

R1

R4

R3

R2

(+) Input

(–) Input

D1

Q1

10 K

10 K

100 nF

100 nF

When an external adapter is connected, the PD70210A WA_EN pin is used for disabling the isolation switch and PSE

input power. The WA_EN pin resistors divider depends on the WA_EN threshold of the PD70210A.

PD70210/PD70210A/PD70210AL

Functional Descriptions

Datasheet

DS00003695A-page 7