AOSMD AOZ1950

AOZ1950
Boost Regulator White LED Driver
General Description
Features
The AOZ1950 is a high-efficiency boost regulator with
internal 60V MOSFET and input protection switch. The
part is designed to drive up to twelve white LEDs in
series. The AOZ1950 supports two dimming control
methods: analog dimming and PWM dimming. In analog
dimming mode, the LED current can be linearly adjusted
for ±12% with a DC voltage on DIM pin. In PWM dimming
mode, the LEDs can be turned on and off by toggling EN
pin with a square wave, and the brightness is
proportional to the duty cycle of the control signal.
AOZ1950 is a fixed OFF pulse regulator with adaptive
pulse width as a function of input and output voltage.
Typical switching frequency is 800kHz. This allows the
use of low-profile inductor and capacitors.
The AOZ1950 works from a 2.7V to 5.5V input voltage
range supporting a wide range of applications. Other
features include cycle-by-cycle current limit, Input voltage
short circuit protection switch, open-LED over-voltage
protection, input under-voltage lockout, thermal
shutdown and soft-start.
z 2.7V to 5.5V input voltage range
The AOZ1950 is available in a tiny 3mm x 3mm
10-pin DFN package and is rated over a -40°C to +85°C
operating temperature range.
z Portable DVD Players
z 60V/350mΩ internal N-channel MOSFET
z Drives up to 12 White LEDs
z 800kHz typical switching frequency with adaptive
pulse width control
z 150ns nominal OFF pulse
z 300mV feedback regulation
z Analog dimming via DIM pin
z PWM dimming via EN pin
z Cycle-by-cycle current limit
z Short circuit protection switch
z Open LED over-voltage protection
z Thermal shutdown protection
z Internal soft-start
z Small 3mm x 3mm DFN package
Applications
z GPS Systems
z Smart Phones
z Sub Notebook PC
Typical Application
L1
22μH
IND
VIN
2.7V-5.5V
VIN
C1
4.7μF
C2
0.47μF
LX
VOUT
AOZ1950
DIM
PGND
AGND
EN
COMP
R1
1.5kΩ
C3
22nF
C4
1nF
FB
Rev. 1.0 January 2010
www.aosmd.com
R2
15Ω
Page 1 of 14
AOZ1950
Ordering Information
Part Number
Ambient Temperature Range
Package
Environmental
AOZ1950DI
-40°C to +85°C
3 x 3 DFN-10
Green Product
RoHS Compliant
AOS Green Products use reduced levels of Halogens, and are also RoHS compliant.
Please visit www.aosmd.com/web/quality/rohs_compliant.jsp for additional information.
Pin Configuration
AOZ1950DI
PGND
1
IND
2
VIN
3
VOUT
4
FB
5
PAD1
(LX)
PAD2
(AGND)
10
LX
9
EN
8
AGND
7
DIM
6
COMP
3x3 DFN-10
(Top View)
Pin Description
Number
Name
Description
1
PGND
2
IND
Top load switch. Connect to inductor.
3
VIN
Input voltage.
4
VOUT
5
FB
6
COMP
7
DIM
8
AGND
9
EN
Power Ground.
Output voltage.
LED Current Feedback Input. The FB voltage is regulated at 300mV in normal operation.
The FB sense resistor sets the nominal LED current.
Compensation pin. Typically connected to RC filter network.
Analog Brightness Control Input. DIM controls the LED brightness by adjusting the LED
current in proportion to DIM voltage. The input range of DIM is between 250mV to
750mV, for -12% and +12% adjustment respectively. When DIM voltage is connected to
VIN, the LED current is 100% of the normal setting.
Controller Ground.
Enable Input. Pull EN high to enable the LED driver output and pull EN low to disable the
LED driver output. The user can use EN pin for PWM dimming. The input frequency
range of EN is between 200Hz and 1kHz.
10
LX
Boost Regulator Switching Node.
PAD1
LX
Boost Regulator Switching Node.
PAD2
AGND
Rev. 1.0 January 2010
Controller Ground.
www.aosmd.com
Page 2 of 14
AOZ1950
Absolute Maximum Rating
Maximum Operating Ratings
Exceeding the Absolute Maximum Ratings may damage
the device
The device is not guaranteed to operate beyond the
Maximum Operating Ratings.
Parameter
Rating
VIN to AGND
Parameter
-0.3V to +6V
LX, VOUT to AGND
Supply Voltage (VIN)
-0.3V to +0.3V
Storage Temperature (TS)
-40°C to +85°C
40°C/W
Package Thermal Resistance
3x3 DFN-10 (ΘJA)
VIN +0.3V
PGND to AGND
2.7V to 5.5V
Ambient Temperature (TA)
-0.3V to +60V
DIM, EN, FB, COMP, IND
Rating
-65°C to +150°C
ESD Rating(1)
2kV
Note:
1. Devices are inherently ESD sensitive, handling
precautions are required. Human body model rating:
1.5kΩ in series with 100pF.
Electrical Characteristics
TA = 25°C, VIN = 3.3V, unless otherwise specified.
Symbol
VVIN
Parameter
Condition
VIN Supply Voltage
Min.
Typ.
2.7
VVIN_UVLO
VIN UVLO Threshold
VIN rising
VVIN_HYS
VIN UVLO Hysteresis
IVIN_ON
VIN Quiescent Current
IVIN_OFF
VIN Shutdown Current
EN = GND
VFB
FB Regulation Voltage
EN = VIN
IFB
FB Input Bias Current
FB = 250mV
TOFF
OFF Pulse Time
VIN = 4.2V, VOUT = 30V
TSS
Soft-Start Time
Number of LEDs = 6
Max.
5.5
V
2.6
V
200
EN = VIN
mV
1.5
285
300
Units
mA
1
μA
315
mV
200
nA
150
ns
2
ms
POWER SWITCH
RNMOS_ON
NMOS On Resistance
EN = VIN, INMOS = 500mA
INMOS_OFF
NMOS Leakage Current
EN = GND, LX = 60V
RPMOS_ON
PMOS On Resistance
EN = VIN, IPMOS = 500mA
0.35
0.55
Ω
2
μA
0.45
0.65
Ω
0.75
1.1
1.35
A
49
53
57
V
PROTECTIONS
ILIM
Current Limit
VVOUT_OVP
OVP Threshold
VVOUT_HYS
OVP Threshold Hysteresis
TSD
Thermal Shutdown Threshold
TSD_HYS
Thermal Shutdown Hysteresis
VOUT Rising
Temperature Rising
4
V
145
°C
35
°C
LOGIC INPUTS
VEN_HIGH
EN Logic High Threshold
VEN_LOW
EN Logic Low Threshold
FPWM_DIM
PWM Dimming Frequency
Range
Rev. 1.0 January 2010
Enable Rising
1.5
0.2
www.aosmd.com
V
0.4
V
1
kHz
Page 3 of 14
AOZ1950
Functional Block Diagram
Reference
Thermal
Detect
Bias
Generator
VOUT
Output
Over Voltage
IND
VIN
Input
UVLO
LX
LED
Logic
Controller
OFF
Pulse
Short
Detect
Over
Current
Driver
Isense
PGND
Analog
Dimming
DIM Detect
Comp
EA
Amp
FB
Soft Start
Enable
PWM
Dimming
EN Detect
COMP
AOZ1950
AGND
Figure 1. Functional Block Diagram
Rev. 1.0 January 2010
www.aosmd.com
Page 4 of 14
AOZ1950
Functional Description
300
250
Pulse Width (ns)
AOZ1950 is a constant off time boost converter that is
ideal for white LED backlight applications. The operating
input voltage range is from 2.7V to 5.5V and can support
up to 12 in series LED’s, with the maximum allowed
output voltage set at 53V. The LED current is set by a
series feedback resistor, located at the bottom of the LED
string. The feedback voltage of the controller is set at
300mV for minimum power loss. AOZ1950 features two
dimming control modes, analog and digital dimming. In
analog dimming, fine adjustment of ±12% of the LED
current can be achieved. In PWM digital dimming, a logic
level pulse width is used to set the output LED current.
The duty cycle of the PWM is proportionally to the LED
current. In this dimming mode, the PWM frequency is set
between from 200Hz to 1kHz with duty cycle from 10% to
100%.
200
VOUT = 5.5V
150
VOUT = 3.3V
100
VOUT = 2.7V
50
0
20
25
30
35
40
45
50
Output Voltage (V)
Figure 3. Pulse Width vs. Output Voltage
Adaptive Constant Pulse Width Control
In a typical constant off time controller, the switching
frequency changes with duty cycle.The duty cycle
relationship of the boost converter entails that if either the
input voltage decreases or the output voltage increases,
the (1-D) off time will decrease. AOZ1950 features an
adaptive constant off-time control that senses the input
and output voltage while maintaining a constant
switching frequency of 800 kHz. In a typical LED
application of 5.5V input and 40V output (12 LEDs), the
off pulse width will be approximately 150ns.
300
VIN = 20V
Pulse Width (ns)
250
Over Current Protection
Under normal operation, cycle by cycle over-current
protection will limit the input peak inductor current from
increasing beyond 1.1A nominally.
Output Short Protection
When an output to ground short is detected, a secondary
short circuit protection current level of 1.3A is activated.
During this event the PMOS input protection switch along
with the output boost switch are disabled simultaneously
and the AOZ1950 will shutdown. The system will restart
with a power cycle when either VIN or EN are toggled.
Over Voltage Protection
200
An over-voltage protection scheme monitors the output
voltage and limits the maximum transient to 53V. The
voltage rating is defined for the maximum voltage stress
of the Mosfet, output boost diode, and output capacitors.
VIN = 36V
150
VIN = 50V
100
50
0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
Input Voltage (V)
Figure 2. Pulse Width vs. Input Voltage
Rev. 1.0 January 2010
www.aosmd.com
Page 5 of 14
AOZ1950
Thermal protection will be activated when the die junction
temperature reaches 145ºC. The system will
automatically restart and lower the junction temperature
to 110ºC.
LED Brightness and Analog Dimming
Applying a voltage between 250mV and 750mV at the
DIM pin will enable analog dimming control for
adjustment of the output LED current. If no adjustment is
required, the DIM pin can be connected to VIN as default.
The percentage of adjustment is set to -12% on the low
end for 250mV and +12% adjustment is obtained when
750mV is applied to the DIM (Figure 4).
30
12 LEDs, L = 22µH
LED Current (mA)
25
VIN = 2.7V, 3.6V 5.5V
For example , if the output LED current is set to 30mA at
100% duty ratio, it will be about 3mA with a duty ratio of
10%. AOZ1950 provides an extremely linear relationship
between 10% to 100% (Figure 5). To accommodate both
PWM both dimming and EN functions with the same pin,
a delay disable of 4.5ms is used to differentiate the
events of PWM dimming OFF period and shutdown of the
chip. The figure below (Figure 6) shows the logic
between the two different modes.
35
12 LEDs, L = 22µH
30
LED Current (mA)
Thermal Protection
VIN = 2.7V, 3.6V 5.5V
25
20
15
10
20
5
15
0
10
20
10
40
50
60
70
80
90
100
PWM Duty Ratio (%)
5
0
0.25
30
Figure 5. Digital Dimming Characteristics
0.35
0.45
0.55
0.65
0.75
VIN Level
Dimming Voltage (V)
EN Pin
Figure 4. Analog Dimming ILED vs. Dimming Voltage
GND Level
tdef > 4.5ms
VIN Level
LED Brightness and Digital Dimming
Digital dimming provides wider range of LED current
adjustment compared to the analog dimming state.
Forcing a digital PWM signal to the EN pin will activate
the system to enter digital dimming mode. The output
boost switch will be completely shutoff when the PWM is
at logic low state and it will switch on when the PWM is at
logic high. The external PWM frequency ranges between
200Hz and 1kHz. In this mode, the output LED current is
averaged based on the duty cycle of the PWM signal.
Rev. 1.0 January 2010
Chip Enable
GND Level
VIN Level
PMOS
Protection
Switch Control
www.aosmd.com
PMOS On
PMOS Off
GND Level
Figure 6. Logic Sequence Differentiating
Dimming Mode and EN Shutdown
Page 6 of 14
AOZ1950
Typical Switching Waveforms
VIN = 5.5V, 6 LEDs
VIN = 5.5V, 12 LEDs
5mS/div
5mS/div
Figure 7. Startup Switching Waveforms
Figure 8. Startup Switching Waveforms
VIN = 5.5V, 12 LEDs
VIN = 5.5V, 6 LEDs
Figure 9. Steady State Waveforms
Figure 10. Steady State Waveforms
VIN = 5.5V, L = 22μH, 12 LEDs
VIN = 5.5V, L = 22μH, 12 LEDs
Figure 11. Output Short to GND Protection
Rev. 1.0 January 2010
www.aosmd.com
Figure 12. Current Limit Off Pulse
Page 7 of 14
AOZ1950
Digital Dimming Characteristics
12 LEDs, fPWM = 1kHz, PWM Duty = 10%
ILED Current
100mA/div
IL Current
(500mA/div)
LX
50V/div
PWM Signal
5/div
500μS/div
12 LEDs, fPWM = 1kHz, PWM Duty = 50%
ILED Current
100mA/div
IL Current
(500mA/div)
LX
50V/div
PWM Signal
5/div
500μS/div
12 LEDs, fPWM = 1kHz, PWM Duty = 90%
ILED Current
100mA/div
IL Current
(500mA/div)
LX
50V/div
PWM Signal
5/div
500μS/div
Figure 13. Digital Dimming Switching Waveforms for PWM Duty Ratio
Rev. 1.0 January 2010
www.aosmd.com
Page 8 of 14
AOZ1950
Application Information
An example of the AOZ1950 application circuit is shown
on page 1. The description below details the component
selection.
LED Current Setting
The feedback voltage (FB) is set to 300mV. The total
output LED current is set by a current sense resistor in
series with the LED string. RSET can be calculated using
EQ.1
V FB
I LED = -------------R SET
(Eq. 1)
Output Capacitor
RSET (Ω)
ILED (mA)
60
5
30
10
20
15
15
20
12
25
10
30
The output ripple voltage specification is key in the
selection of the output capacitor. In a boost converter, the
output ripple voltage is determined by load current, input
voltage, output voltage, switching frequency, output
capacitor value and ESR. It can be calculated by the
equation below: The voltage rating of the output
capacitor must be higher than the intended output boost
voltage plus the output ripple voltage. Therefore some
de-rating is required for ensure long term reliability.
Input Capacitor
The input capacitor is connected to VIN and GND pins of
the AOZ1950 to filter and maintain a steady input DC
voltage. The voltage rating of input capacitor must be
greater than maximum input voltage plus ripple voltage.
The RMS current rating should be greater than the
inductor ripple current:
The input capacitor value should be 4.7μF or higher for
normal operation. The capacitor can be electrolytic,
tantalum or ceramic. The input capacitor should be place
as close as possible to the IC; if not possible, a 0.1μF
decoupling ceramic capacitor between VIN pin and GND
in close proximity.
Inductor
The inductor is used to supply higher output voltage
when the NMOS switch is off. For a given input and
output voltage, the inductance and switching frequency
determine the inductor ripple current, defined as,
V OUT – V IN
(Eq. 2)
I Lripples = ------------------------------ × T OFFPULSE
L
The peak inductor current is:
ΔI L
I Lpeak = I IN + -------2
Rev. 1.0 January 2010
(Eq. 3)
Higher boost inductance will yield lower inductor ripple
current but this will require an inductor with higher
saturation current rating at the highest operating
temperature. Lower ripple current helps to reduce
inductor core losses. It also reduces RMS current
through inductor, switch and freewheeling diode, which
results in less conduction loss. The peak to peak ripple
current of the inductor should be between 30% to 50% of
input current. An inductor value of 22μH is recommended
for 6 to 12 LED operation.
V IN ⎞ ⎞
⎛
⎛
⎜ 1 – ---------------⎟ ⎟
⎜
V OUT⎠ ⎟
⎝
⎜ VO
ΔV O = I LED × ⎜ --------- × ESR CO + ------------------------------⎟
f × C OUT ⎟
⎜ V IN
⎜
⎟
⎝
⎠ (Eq. 4)
V IN
f = --------------------------------- (Eq. 5)
V OUT × t OFF
where,
ILED is the load current or LED current,
COUT is output capacitor value and
ESRCO is the Equivalent Series Resistor of output capacitor.
When low ESR ceramic output capacitors are used, the
impedance of the capacitor at the switching frequency
dominates. Output ripple is mainly caused by capacitor
value and load current with the frequency, input and
output voltage. The output ripple voltage calculation can
be simplified to:
V IN ⎞ (Eq. 6)
⎛
⎜ 1 – ---------------⎟
V OUT⎠
⎝
ΔV O = I L × -----------------------------f × C OUT
www.aosmd.com
Page 9 of 14
AOZ1950
The closed loop transfer function
An output capacitor with the value in the range of
2.2μF to 4.7μF is usually sufficient to meet most
applications requirements.
Output Boost Diode
A low forward drop Schottky with fast transit time should
be selected to improve converter efficiency.
Its current rating should be higher than the peak current
that commutates during its conduction interval. In
addition, the rated breakdown voltage should be higher
than the application boost voltage plus some margin of
transient overshoot.
Loop Compensation
AOZ1950 employs constant off time control and does not
require slope compensation. The right half plane zero
that is often problematic in all most boost converters has
no significant effect in the AOZ1950’s frequency
response. The RHP zero has the effect of a zero in the
gain causing +20dB/decade on the roll off, but has the
effect of a pole in the phase, subtracting 90o in the
phase. The RHP zero can cause instability issues if the
bandwidth is higher, therefore it is recommended to lower
the bandwidth by one half frequency of the RHP zero.
The RHPZ can be calculated as follows:
2
D P ( I LOAD ) × R OUT ( I LOAD )
f RHPZ = --------------------------------------------------------------------------2π × L
(Eq. 7)
where,
P1
The corresponding pole is:
1
f P1 = --------------------------------------------------- (Eq. 12)
2π × R EA × C COMP
The corresponding zero is:
1
f Z = ---------------------------------------------------------------- (Eq. 13)
R COMP × R EA
------------------------------------× C COMP
R COMP + R EA
where,
GM is the error amplifier transconductance, which is
150·10-6 A/V,
REA = 1MΩ,
CCOMP is compensation capacitor,
RCOMP is compensation capacitor
A compensation resistor and capacitor value of 1.5kΩ
and a 22nF along with a filter capacitor of 1nF from
COMP to GND is recommended for a typical 12 LED
application.
Circuit Layout and Thermal management
D P ( I LOAD ) = 1 – D ( I LOAD ) (Eq. 8)
V OUT ( I LOAD )
R OUT ( I LOAD ) = ------------------------------------ (Eq. 9)
I LOAD
The cross over frequency in typical applications should
be a fifth of the frequency of the RHPZ location
f RHPZ (Eq. 10)
f CROSS = ---------------5
The objective of compensation is to shape the gain and
phase of the converter’s closed loop transfer function
ultimately to achieve stability. The compensation pin of
AOZ1950 is serves as the output of the voltage
transconductance error amplifier. In a typical application,
a series capacitor and resistor network connected to the
COMP pin creates the pole-zero compensation network
enabling a very stable high-bandwidth control loop.
Rev. 1.0 January 2010
s(w)
G M × R EA × ⎛ 1 + ------------⎞ (Eq. 11)
⎝
wz ⎠
H ( w ) = -----------------------------------------------------------( w )⎞
⎛ 1 + s----------⎝
w ⎠
To minimize unwanted noise and voltage transients,
careful PCB layout must be exercised to reduce the main
current loop areas. This optimization helps to reduce the
switching noise associated with current commutation in
the circuit and also helps to improve the efficiency of the
converter. In addition to reducing the main power loops it
is also important to keep sensitive nodes such as
compensation and enable pins in quieter ground areas
away from the main power ground connection.
In the AOZ1950 boost LED driver circuit, there are two
main switching loops that pulsate current flow when the
NMOS turns on and off. The first loop starts when the
NMOS switches on, the input current or inductor current
ramps positively through the inductor and NMOS device.
During this interval, the output boost diode is reversed
biased with its anode pulled low to ground. Since the
NMOS is internal in the AOZ1950 much of the parasitic
inductance is made from the power return to the ground
connection of the input capacitors.
www.aosmd.com
Page 10 of 14
AOZ1950
Based on the duty cycle arrangement, the controller will
signal the internal driver to turn-off the NMOS to initiate
the fixed off time. After the NMOS is fully off, the
continuous inductor current continues to freewheel
through the output boost diode. The key parasitics in this
loop consist of PBC trace inductance from the anode to
the LX connection and lastly the connection from cathode
to power ground return. Both input and output capacitors
should be ceramic in type to achieve low ESR and ESL
specifications.
Alpha and Omega
LED Boost Driver
C1
AOZ1950
LED Boost Driver
L1
VIN
AOZ1950DI
D1
RCOMP GND
RSET
EN
C COMP
PGND
1
IND
10
LX
2
9
EN
VIN
3
8
AGND
VOUT
4
7
DIM
FB
5
6
COMP
PAD1
(LX)
LX
COUT
PAD2
(AGND)
CC
DIM
vOUT
LED
STRING
3x3 DFN-10
(Top View)
Figure 14. Example of AOZ1950 PCB Layout and DFN-10 Pin-out
1. Maximized the copper area to the GND pin and the
VIN pin for improved thermal dissipation.
In the AOZ1950 boost regulator circuit, the three major
power dissipating components are the AOZ1950 and
output inductor. The total power dissipation of converter
circuit can be measured by difference between the input
and output power.
2. Incorporate a ground plane on both top and bottom
layers if possible.
P total_loss = ( V IN × I IN ) – ( V O × I O ) (Eq. 14)
3. To minimize trace inductance connects the device to
the LX pin with a short wire and adoption of this
technique for connections to the output capacitor and
ground.
The power dissipation of inductor can be approximately
calculated by input current and DCR of inductor.
4. Add thermal vias for the GND pad for improved
thermal dissipation between top and bottom layers.
The actual AOZ1950 junction temperature can be
calculated with power dissipation and the thermal
impedance from junction to ambient.
Below are some key tips in minimize the two main
switching loops and improving noise immunity
5. To maximize thermal dissipation pour incorporate
copper planes in unused areas.
6. Route sensitive signals such as FB and COMP
pins a far distance away from the LX switching node
and pin.
Rev. 1.0 January 2010
P inductor_loss = I
IN
2
× R inductor × 1.1 (Eq. 15)
T junction = ( P total_loss – P inductor_loss ) × Θ + T amb
(Eq. 15)
The maximum junction temperature of AOZ1950 is rated
at 145ºC The thermal performance of the AOZ1950 is
strongly affected by the PCB layout and proper care
should be taken to ensure that the device will operate
under the recommended environmental conditions.
www.aosmd.com
Page 11 of 14
AOZ1950
Package Dimensions, DFN3X3 10L EP2
D
A
2
INDEX AREA
(D/2xE/2)
B
D/2
PIN #1 IDA
L1
e
1
L
E/2
E
R
E1
L3
L3
E1/2
L2
D1
TOP VIEW
D2
BOTTOM VIEW
A
A1
A3
C
Seating
Plane
4
ddd
b
3
SIDE VIEW
Dimensions in millimeters
RECOMMENDED LAND PATTERN
0.50
0.23
0.50
1.35
Symbols
Min.
Nom.
A
A1
0.80
0.00
A3
b
D
0.20
0.90
0.02
0.20 REF
0.23
D1
0.50
D2
1.24
0.57
1.70
0.85
2.70
0.1 x 45°
0.70
0.27
0.27
E1
e
L
L1
L2
L3
Min.
1.00
0.05
A
A1
0.031
0.000
0.33
A3
b
D
0.65
0.75
D1
0.020
0.026
0.030
1.39
1.49
D2
0.049
0.055
0.059
3.00 BSC
E
Dimensions in inches
Symbols
Max.
1.70
0.50 BSC
0.28
0.38
0.47
0.57
0.07
0.17
0.27 REF.
1.80
0.48
0.67
0.27
0.118 BSC
0.118 BSC
E1
e
L
L1
L2
L3
0.061
0.067
0.020 BSC
0.011
0.015
0.019
0.022
0.003
0.007
0.011 REF.
0.006 REF
R
0.15 REF
R
0.17
aaa
0.15
aaa
0.006
1.44
bbb
0.10
bbb
ccc
0.10
ccc
0.004
0.004
ddd
0.08
ddd
0.003
Unit: mm
Max.
0.035
0.039
0.001
0.002
0.008 REF
0.008
0.009
0.013
E
3.00 BSC
1.55
Nom.
0.071
0.019
0.026
0.011
Notes:
1. All dimensions are in millimeters.
2. The location of the terminal #1 identifier and terminal numbering convention conforms to JEDEC
publication 95 SPP-002.
3. Dimension b applies to metallized terminal and is measured between 0.20mm and 0.35mm from the terminal tip.
If the terminal has the optional radius on the other end of the terminal, the dimension b should not be
measured in that radius area.
4. Coplanarity applies to the terminals and all other bottom surface metallization.
Rev. 1.0 January 2010
www.aosmd.com
Page 12 of 14
AOZ1950
Tape and Reel Dimensions, DFN3X3 10L EP2
Tape
D0
D1
A A
E1
A
P1
K0
E2
E
B0
A
T
P0
A0
P2
Feeding Direction
UNIT: MM
Package
A0
B0
K0
D0
D1
E
E1
E2
P0
P1
P2
T
DFN 3x3 EP
3.40
±0.10
3.35
±0.10
1.10
±0.10
1.50
+0.10
-0
1.50
+0.10
-0
12.00
±0.30
1.75
±0.10
5.50
±0.05
8.00
±0.10
4.00
±0.10
2.00
±0.05
0.30
±0.05
Reel
W1
S
G
M
N
K
V
R
H
W
UNIT: mm
Tape Size Reel Size
M
N
W
12mm
ø330
ø330.00 ø97.00 13.00
±0.50
±0.10 ±0.30
W1
H
17.40
ø13.00
±1.00 +0.50 / -0.20
K
10.60
S
2.00
±0.50
G
-
R
-
V
-
Leader/Trailer and Orientation
Trailer Tape
300mm min.
Rev. 1.0 January 2010
Components Tape
Orientation in Pocket
www.aosmd.com
Leader Tape
500mm min.
Page 13 of 14
AOZ1950
Package Marking
AOZ1950DI
(DFN 3x3 10L)
1950
I0AW
LT
Industrial Temperature Range
No Option
Week
(Year code is embedded by using
upper under bar under dot on W)
Assembly Location
Assembly Lot Number
This data sheet contains preliminary data; supplementary data may be published at a later date.
Alpha & Omega Semiconductor reserves the right to make changes at any time without notice.
LIFE SUPPORT POLICY
ALPHA & OMEGA SEMICONDUCTOR PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL
COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS.
As used herein:
1. Life support devices or systems are devices or
systems which, (a) are intended for surgical implant into
the body or (b) support or sustain life, and (c) whose
failure to perform when properly used in accordance
with instructions for use provided in the labeling, can be
reasonably expected to result in a significant injury of
the user.
Rev. 1.0 January 2010
2. A critical component in any component of a life
support, device, or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or
effectiveness.
www.aosmd.com
Page 14 of 14