ADP5062CP-EVALZ Analog Devices, ADP5062CP-EVALZ Datasheet - Page 39

• Manufacturer Part Number: ADP5062CP-EVALZ
• Description: Power Management IC Development Tools ADP5062 Evaluation board
• Manufacturer: Analog Devices
• Type: Linear Regulators - Standardr
• Series: ADP5062r

Specifications of ADP5062CP-EVALZ

• Rohs: yes
• Product: Evaluation Boards
• Tool Is For Evaluation Of: ADP5062
• Input Voltage: 4 V to 6.7 V
• Description/function: Battery charger (isolated flyback)
• Interface Type: I2C
• Maximum Operating Temperature: + 125 C
• Minimum Operating Temperature: - 40 C
• Output Current: 2.1 A
• Factory Pack Quantity: 1
• For Use With: ADP5062

Data Sheet
POWER DISSIPATION AND THERMAL CONSIDERATIONS
CHARGER POWER DISSIPATION
When the
tures and at maximum current charging and loading conditions,
the junction temperature can reach the maximum allowable
operating limit of 125°C.
When the junction temperature exceeds 140°C, the
turns off, allowing the device to cool down. When the die
temperature falls below 110°C and the TSD 140°C fault bit in
Register 0x0D is cleared by an I
normal operation.
This section provides guidelines to calculate the power dissi-
pated in the device to ensure that the
the maximum allowable junction temperature.
To determine the available output current in different operating
modes under various operating conditions, use the following
equations:
where:
P
P
Calculate the power dissipation in the LDO FET and the battery
isolation FET using Equation 2 and Equation 3.
where:
V
V
V
I
I
LDO Mode
The system regulation voltage is user-programmable from 4.3 V
to 5.0 V. In LDO mode (charging disabled, EN_CHG = low),
calculation of the total power dissipation is simplified, assuming
that all current is drawn from the VINx pins and the battery is
not shared with ISO_Sx.
Charging Mode
In charging mode, the voltage at the ISO_Sx pins depends on
the battery level. When the battery voltage is lower than V
(typically 3.8 V), the voltage drop over the battery isolation FET
CHG
LOAD
LDOFET
ISOFET
ISO_Sx
IN
ISO_Bx
is the input voltage at the VINx pins.
is the battery charge current.
P
P
P
P
is the system load current from the ISO_Sx pins.
is the system voltage at the ISO_Sx pins.
D
LDOFET
ISOFET
D
is the power dissipated in the battery isolation FET.
is the battery voltage at the ISO_Bx pins.
is the power dissipated in the input LDO FET.
= P
= (V
ADP5062
LDOFET
= (V
= (V
IN
– V
ISO_Sx
IN
+ P
ISO_Sx
– V
ISOFET
charger operates at high ambient tempera-
– V
ISO_Sx
) × I
ISO_Bx
) × (I
LOAD
) × I
2
CHG
C write, the
CHG
+ I
ADP5062
LOAD
)
ADP5062
operates below
ADP5062
resumes
ISO_SFC
Rev. 0 | Page 39 of 44
(1)
(2)
(3)
is higher and the power dissipation must be calculated using
Equation 3. When the battery voltage level reaches V
power dissipation can be calculated using Equation 4.
where:
R
(typically 110 mΩ during charging).
I
The thermal control loop of the
the charge current to maintain a die temperature below T
(typically 115°C).
The most intuitive and practical way to calculate the power
dissipation in the
dissipated at the input and all of the outputs. Perform the
measurements at the worst case conditions (voltages, currents,
and temperature). The difference between input and output
power is the power that is dissipated in the device.
JUNCTION TEMPERATURE
In cases where the board temperature, T
thermal resistance parameter, θ
junction temperature rise. T
the formula
The typical θ
Table 5). A very important factor to consider is that θ
on a 4-layer, 4 in × 3 in, 2.5 oz. copper board as per JEDEC
standard, and real-world applications may use different sizes
and layers. It is important to maximize the copper to remove the
heat from the device. Copper exposed to air dissipates heat
better than copper used in the inner layers.
If the case temperature can be measured, the junction
temperature is calculated by
where T
thermal resistance provided in Table 5.
The reliable operation of the charger can be achieved only if the
estimated die junction temperature of the
is less than 125°C. Reliability and mean time between failures
(MTBF) are greatly affected by increasing the junction temperature.
Additional information about product reliability can be found in
the ADI Reliability Handbook located at the following URL:
www.analog.com/reliability_handbook.
CHG
DSON_ISO
is the battery charge current.
P
T
T
ISOFET
J
J
= T
= T
C
is the on resistance of the battery isolation FET
is the case temperature and θ
A
C
= R
+ (P
+ (P
JA
DSON
value for the 20-lead LFCSP is 35.6°C/W (see
D
D
ADP5062
× θ
× θ
_
ISO
JC
JA
× I
)
)
CHG
J
device is to measure the power
is calculated from T
JA
ADP5062
, can be used to estimate the
JC
A
is the junction-to-case
ADP5062
, is known, the
automatically limits
A
ADP5062
and P
(Equation 5)
ISO_SFC
JA
is based
D
LIM
using
, the
(4)
(5)
(6)