AAT2610_12 Datasheet, PDF (25/31 Pages) Skyworks Solutions Inc. – Seven-Channel PMU for Digital Still Cameras

DATA SHEET
AAT2610
Seven-Channel PMU for Digital Still Cameras
Manufacturer Value (µF)
1
1
3.3
Murata
4.7
4.7
10
22
Voltage (V)
25
10
10
25
6.3
6.3
6.3
Case Size
0603
0603
0603
0805
0603
0805
0805
Part Number
GRM188R61E105K
GRM185R61A105K
GRM188R61A335K
GRM21BR61E475K
GRM188R60J475K
GRM219R60J106KE19
GRM21BR60J226M
Channel / Capacitor
Position
AUX1 / output
SD1, SD2, AUX1, AUX2,
AUX3 / input
AUX3 / output
AUX2 / output
SU, Main / input
Main SD, SD1, SD2 / output
Main SU, SD1, SD2
SU, Main SU / output
Table 4: Suggested Input and Output Capacitor Selection Information.
Output Diode
A Schottky diode is suitable in the three non-synchronous
step-up channels for its low forward voltage and fast
recovery time. 20V rated Schottky diodes are recom-
mended for outputs less than 10V, while 30V rated
Schottky diodes are recommended for outputs greater
than 10V. Table 5 shows suggested diode part numbers.
Using SEQ for Power Sequence
Power sequence delay is designed to connect the loads
to Main channel output after its normal startup. Use the
SEQ output signal to control an external PMOSFET con-
nected between Main output and loads. The SEQ output
is high impedance lasted for 10ms when startup, then
pulled low after both the SD1 and SD2 converters com-
pleted soft-start and achieved output regulation. When
SD1 and SD2 are disabled, SEQ is also pulled low after
10ms when Main channel achieves regulation.
Using SCF for Full-Load Startup
SCF goes high (high impedance, open drain) when over-
load protection occurs. Under normal operation, SCF
pulls low. It can be used to drive a P-channel MOSFET
switch that turns off the load of a selected supply in the
event of an overload. Or, it can remove the load until the
supply reaches regulation, effectively allowing full load
startup.
Thermal Considerations
Thermal design is an important aspect of power manage-
ment IC applications and PCB layout. The AAT2610
TQFN55-40L package can provide up to 2W of power dis-
sipation when it is properly soldered onto a printed circuit
board with thermal vias. The package has a maximum
thermal resistance of 25°C/W. The maximum power dis-
sipation in a given ambient condition can be calculated:
P_D(MAX) =
(T_J(MAX) - T_A)
θ_JA
Where:
P_D(MAX) = Maximum Power Dissipation (W)
θ_JA = Package Thermal Resistance (°C/W)
T_J(MAX) = Maximum Device Junction Temperature (°C)
[150°C]
T_A = Ambient Temperature (°C)
The power dissipation for the synchronous buck channel
in CCM (Continuous Conduction Mode) can be calculated
by the following equation:
P_Syn-BUCK = I_OUTBUCK2 ·
R_DS(ON)P ·
V_INBUCK
V_OUTBUCK
+
R_DS(ON)N
·
1-
V_INBUCK
V_OUTBUCK
Where:
P_Syn-BUCK = Synchronous Buck Channel Power Dissipation
I_OUTBUCK = Synchronous Buck Channel Output Current
V_OUTBUCK = Synchronous Buck Channel Output Voltage
V_INBUCK = Synchronous Buck Channel Input Voltage
R_DS(ON)x = Synchronous Buck Channel PMOS or NMOS
Drain-Source On Resistance
Skyworks Solutions, Inc. • Phone [781] 376-3000 • Fax [781] 376-3100 • [e-mail] • www.skyworksinc.com
202208A • Skyworks Proprietary Information • Products and Product Information are Subject to Change Without Notice. • July 25, 2012
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