ADUM3070 AD [Analog Devices], ADUM3070 Datasheet - Page 17

• Manufacturer Part Number: ADUM3070
• Description: Isolated Switching Regulator
• Manufacturer: AD [Analog Devices]

Data Sheet
Table 14. Recommended Components
Part Number
GRM32ER71A476KE15L
GRM32ER71C226KEA8L
GRM31CR71A106KA01L
MBR0540T1/D
LQH3NPN470MM0
ME3220-104KL
PRINTED CIRCUIT BOARD (PCB) LAYOUT
Note that the total lead length between the ends of the low ESR
capacitor and the V
Figure 34 for the recommended PCB layout.
In applications involving high common-mode transients, ensure
that board coupling across the isolation barrier is minimized.
Furthermore, design the board layout such that any coupling
that does occur equally affects all pins on a given component side.
Failure to ensure this can cause voltage differentials between pins,
exceeding the absolute maximum ratings specified in Table 10,
thereby leading to latch-up and/or permanent damage.
The
power when fully loaded. Because it is not possible to apply a
heat sink to an isolation device, the device primarily depends on
heat dissipation into the PCB through the GND
is used at high ambient temperatures, care must be taken to provide
a thermal path from the GND
GND
V
GND
ADuM3070
DDA
X1
X2
1
1
Figure 34. Recommended PCB Layout
is a power device that dissipates about 1 W of
NC
TP
TP
DDx
and GND
Manufacturer
Murata
Murata
Murata
ON Semiconductor
Murata
Coilcraft
x
pins to the PCB ground plane.
x
pins must not exceed 2 mm. See
NOTES
1. V
2. V
I
IN
DD1
DDA
V
V
DD1
DDA
NC
NC
IS THE POWER SUPPLY FOR THE PUSH-PULL TRANSFORMER.
IS THE POWER SUPPLY OF SIDE 1 OF THE ADuM3070.
I
DD1
x
I
DDA
pins. If the device
Value
47 µF, 10 V, X7R,
1210
22 µF, 16 V, X7R,
1210
10 µF, 10 V, X7R,
1206
0.5 A, 40 V,
Schottky, SOD-123
47 µH, 0.41 A,
1212
100 µH, 0.34 A,
1210
X1
GND1
CONVERTER/
V
GND
V
FB
OC
GND
PRIMARY
REG
DD2
DRIVER
2
2
X2
Figure 35. Supply Currents
Rev. 0 | Page 17 of 20
ADuM3070
FEEDBACK
INTERNAL
GND2
CONTROLLER
SECONDARY
RECT
The board layout shows enlarged pads for the GND
and Pin 8) on Side 1 and (Pin 9 and Pin 15) on Side 2. Implement
large diameter vias from the pad to the ground planes and power
planes to increase thermal conductivity and to reduce inductance.
Multiple vias in the thermal pads can significantly reduce
temperatures inside the chip. The dimensions of the expanded
pads are left to the discretion of the designer and the available
board space.
THERMAL ANALYSIS
The
split lead frame with two die attach paddles. For the purposes of
thermal analysis, the die is treated as a thermal unit, with the
highest junction temperature reflected in the θ
The value of θ
mounted on a JEDEC standard, 4-layer board with fine width traces
and still air. Under normal operating conditions, the
devices operate at full load across the full temperature range
without derating the output current. However, following the
recommendations in the Printed Circuit Board (PCB) Layout
section decreases thermal resistance to the PCB, allowing increased
thermal margins in high ambient temperatures. The
has a thermal shutdown circuit that shuts down the dc-to-dc
converter of the
160°C is reached. When the die cools below about 140°C, the
ADuM3070
POWER CONSUMPTION
The total input supply current is equal to the sum of the I
transformer current and the
The following relationship allows the total I
where:
I
I
E is the power supply efficiency at the given output load from
Figure 8 or Figure 14 at the V
IN
ISO
is the total supply input current.
is the current drawn by the secondary side external load.
ADuM3070
I
REG
IN
V
= (I
REG
ISO
dc-to-dc converter turns on again.
JA
× V
V
FB
OC
is based on measurements taken with the devices
DD2
parts consist of two internal die attached to a
ADuM3070
ISO
5V
V
)/(E × V
ISO
I
ISO
DD1
when a die temperature of about
ADuM3070
ISO
)
and V
DD1
input current, I
condition of interest.
IN
current to be:
JA
ADuM3070
from Table 5.
ADuM3070
x
ADuM3070
DD1
pins (Pin 2
primary
DDA
.
(1)