SC604A
Low Noise, High Efficiency
Regulated White LED Driver
POWER MANAGEMENT
OBJECTIVE
Description -NOVEMBER
Features
9,
2000
Very high efficiency over 90% of battery life
The SC604A is a very high efficiency charge pump white
Peak efficiency over 92%
Current regulation for up to 4 LEDs
Digital 3 bit output control logic
Current matching tolerance of ±3% typical
Wide current range per LED [0.5mA - 30mA]
High available total LED current = 4 ILED = 120mA
Low Shutdown Current: 1µA typical
Soft start / In-rush current limiting
Short circuit protection
MLP-16 [4x4] Package
Fixed frequency 250kHz
1x, 1.5x and 2x charge pump modes of operation
LED driver driver from the mAhXLifeTM family of products,
optimized for Li-Ion battery applications.
The four (4) LED outputs are current matched for consistent LED brightness. Extremely low battery current is
achieved by automatically reconfiguring the charge pump
to match circuit conditions. Using four LEDs, each at
20mA for a total IOUT= 80mA, the SC604A can use less
than 83mA from the supply for most of the battery life.
Patented low noise mode switching circuitry and constant
output current allow the use of extremely small input and
output capacitors.
Applications
Cellular phones
LED backlighting
PDA power supplies
Portable devices
Typical Application Circuit
Patent Pending
VIN
BATTERY
Electronic books
Wireless web appliances
LCD Modules
VOUT
1µF
1µF
SC604A
EN
CTRL0
ILED1
ILED2
ILED3
ILED4
CTRL1
CTRL2
GND
C1+
ISET
C1-
C2+
C2-
1µF
1µF
June 27, 2005
1
United States Patents: 6,504,422, 6,794,926
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SC604A
POWER MANAGEMENT
Absolute Maximum Ratings
Exceeding the specifications below may result in permanent damage to the device, or device malfunction. Operation outside of the parameters
specified in the Electrical Characteristics section is not implied.
Parameter
Symbol
Maximum
Units
Sup p ly Voltage
V IN
-0.3 to +7.0
V
Outp ut Voltage
VOUT
-0.3 to +7.0
V
VOUT Shor t Circuit Duration
SC
Indefinite
s
θJ A
40
°C/W
Op erating Ambient
TA
-40 to +85
°C
Junction Temp erature Range
TJ
-40 to +150
°C
Storage Temp erature Range
TSTG
-65 to +150
°C
IR Reflow Temp erature SC604AIMLTR
T LE A D
240
°C
IR Reflow Temp erature SC604AIMLTRT
T LE A D
260
°C
Thermal Resistance, Junction to Ambient
(1)
Note: (1) By JESD51 standards
Electrical Characteristics
Unless specified: TA = -40°C to 85°C, VIN= 2.85V to 5.5V, C1 = C2 = 1.0µF (ESR = 0.03Ω). Typical values @ TA=25°C, LED VF = 3.4V.
This device is ESD sensitive. Use of standard ESD handling precautions is required.
Parameter
Symbol
Inp ut Sup p ly Voltage
V IN
Current into LEDs
1, 2, 3 and 4
IL E D
Conditions
Min
Typ
2.5
Ma x
Units
6.5
V
RSET = 24.0kΩ
20
mA
RSET = 94.0kΩ
5.0
mA
2.7V < VIN < 5.5V
0.5
20
mA
3.1V < VIN < 5.5V
0.5
30
mA
IOUT = 5mA
1500
2000
µA
Enable = 0V
1
7
µA
ILED-ERR
0.5mA ≤ ILED ≤ 30mA
±5
%
ILED-LED-ERR
0.5mA ≤ ILED ≤ 30mA
±3
%
1x mode to 1.5x mode
transition voltage (VIN falling)
VTRANS1X
VLED = 3.6V, IOUT = 80mA, ILED = 20mA
3.796
V
1.5x mode to 2x mode
transition voltage (VIN falling)
VTRANS1.5X
VLED = 3.6V, IOUT = 80mA, ILED = 20mA
3.320
V
Quiescent Current
ILED Accuracy
Current Matching
IQ
Oscillator Frequency
fOSC
Outp ut Over Voltage
Protection (1)
VOVP
212.5
Op en circuit at any LED that is
p rogrammed to be in the On state
2005 Semtech Corp.
5.0
250
287.5
kHz
V
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2
SC604A
POWER MANAGEMENT
Electrical Characteristics (Cont.)
Unless specified: TA = -40°C to 85°C, VIN= 2.85V to 5.5V, C1 = C2 = 1.0µF (ESR = 0.03Ω). Typical values @ TA=25°C, LED VF = 3.4V.
Parameter
Symbol
Conditions
IL IM IT
Shor t circuit ap p lied from VOUT to GN D
Inp ut High Threshold
V IH
Inp ut high logic threshold
Inp ut Low Threshold
V IL
Inp ut low logic threshold
0.4
V
Inp ut High Current
I IH
VIH= VIN
10
µA
Inp ut Low current
I IL
VIL= GN D
10
µA
Inp ut Current Limit
Min
Typ
Ma x
Units
220
850
mA
V
1.3
Notes:
(1) Guaranteed by design
2005 Semtech Corp.
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SC604A
POWER MANAGEMENT
Definitions
Input Current
The total input current of the SC604A is a function of
the sum of the LED currents, the charge pump mode
and the quiescent current. The quiescent current trend
is charted on page 12 and used to calculate IIN in the
following examples.
ILED Accuracy
The LED current is determined by the RSET resistor (ILED
vs. RSET data is found on pages 9 and 10). This term
does not include the tolerance of the resistor RSET. If
maximum accuracy is required, a precision resistor is
needed. To calculate the error ILED-ERR[%], use the formula
ILED-ERR [%] = ±
(I LED ) MEASURED
IIN = IOUT Mode + IQ =
- I LED
100 %
I LED
(ILED1+ILED2+ILED3+ILED4 ) Mode + IQ
Current Matching
Current Matching refers to the difference in current from
one LED to the next. The ∆I between any two LEDs will
meet this requirement. To calculate the error ILED-LED-ERR ,
first identify the highest and lowest value of the 4 LED
currents, and use the formula:
ILED-LED-ERR [%] =
IMAX
IMAX + IMIN
-1
100%
-1
100%
Example 1:
Mode = 1x, IQ = 2.4mA,
ILED1+ILED2+ILED3+ILED4 = 4 15mA = 60mA
Answer 1:
IIN = IOUT
62.4mA
2
or
IMIN
IMAX + IMIN
IMAX
IMIN
IMAX + IMIN
1 + 2.4mA =
Example 2:
Mode = 1.5x, IQ = 2.4mA,
ILED1+ILED2+ILED3+ILED4 = 4 15mA = 60mA
2
which reduces to ±
Mode + IQ = 60mA
Answer 2:
100%
IIN = IOUT
Mode + IQ = 60mA
1.5 + 2.4mA =
92.4mA
1x Mode, 1.5x Mode and 2x Mode
1x Mode, 1.5x Mode and 2x Mode all refer to the charge
pump configuration. These modes boost the battery input
voltage and ensure there is enough voltage at VOUT so
that the regulated current will flow through the LEDs and
return via the ILED pins.
Mode Transition Voltage
Mode transition voltage refers to the input voltage at
the point just before the charge pump changes from a
weaker mode to a stronger mode. V TRANS1X is the
transition from 1x to 1.5x mode, and VTRANS1.5X is the
transition from 1.5x to 2x mode. Equations for VTRANS1X
and VTRANS1.5X are given on page 7.
2005 Semtech Corp.
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SC604A
POWER MANAGEMENT
Pin Configuration
Ordering Information
TOP VIEW
ILED1 ILED2 ILED3 ILED4
16
14
12
2
11
C2+
3
10
1
CTRL0
CTRL1
TOP VIEW
T
4
5
ISET
6
9
7
VOUT VIN
PACKAGE(1)
SC604AIMLTR
MLP-16
SC604AIMLTRT(2)
MLP-16
SC604EVB
Evaluation Board
13
GND
EN
CTRL2
15
DEVICE
Notes:
(1) Available in tape and reel only. A reel contains 3000 devices.
(2) Available in lead-free package only. This product is fully WEEE and
RoHS compliant.
C2C1-
8
C1+
MLPQ16: 4X4 16 LEAD
Pin Descriptions
Pin
Pin Name
Pin Function
1
EN
2
CTRL0
Outp ut control bit 0 (see Table 1 on p age 6)
3
CTRL1
Outp ut control bit 1 (see Table 1 on p age 6)
4
CTRL2
Outp ut control bit 2 (see Table 1 on p age 6)
5
ISET
LED current is set by the value of the resistor RSET connected from the ISET p in to ground. Do not
shor t the ISET p in. VISET is typ ically 1.22V
6
VOUT
Voltage outp ut source for connection to the LED anodes
7
V IN
Voltage inp ut
8
C1+
Positive terminal of bucket cap acitor 1
9
C1-
N egative terminal of bucket cap acitor 1
10
C2-
N egative terminal of bucket cap acitor 2
11
C2+
Positive terminal of bucket cap acitor 2
12
GN D
Ground
13
ILED4
Current sink for LED 4 [lf not in use, p in must be left op en](1)
14
ILED3
Current sink for LED 3 [lf not in use, p in may be left op en, grounded, or connected to VIN](1)
15
ILED2
Current sink for LED 2 [lf not in use, p in may be left op en, grounded, or connected to VIN](1)
16
ILED1
Current sink for LED 1 [lf not in use, p in may be left op en, grounded, or connected to VIN](1)
T
Active high enable
Thermal Pad Pad for heatsinking p urp oses. Connect to ground p lane using multip le vias. N ot connected Internally
Note: (1) The CTRL word must match the outputs in use.
2005 Semtech Corp.
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SC604A
POWER MANAGEMENT
Block Diagram
C1+
8
VOUT
C210
C19
C2+
11
ILED4
ILED3
ILED2
ILED1
13
14
15
16
Current Brightness Control
6
mAhXLifeTM Fractional Charge Pump
[1x, 1.5x, 2x]
VIN
12 GND
Current Sense FETs
and Amplifier(s)
7
Current Set Detect
250kHz
Oscillator
& Delay Clk
EN
1
Mode Select
[1x, 1.5x, 2x
Startup, Shutdown]
Ouput Selection
Logic
5
ISET
2
CTRL0
3
CTRL1
4
CTRL2
1.22V Bandgap
Voltage
Schmitt Buffer
Schmitt Buffer
Schmitt Buffer
Schmitt Buffer
Table 1 - LED Enable Logic
Control Inputs
Output Status
(1)
CTR L2
CTR L1
CTR L0
LED4
LED3
LED2
LED1
0
0
0
OFF
OFF
OFF
ON
0
0
1
OFF
OFF
ON
OFF
0
1
0
OFF
ON
OFF
OFF
0
1
1
ON
OFF
OFF
OFF
1
0
0
OFF
OFF
ON
ON
1
0
1
OFF
ON
ON
ON
1
1
0
ON
ON
ON
ON
1
1
1
OFF
OFF
OFF
OFF
Notes:
(1) The sequencing of Enable and logic state CTRL{2,1,0} = [1, 1, 1] will affect quiescent state current. IQ = 100µA if Enable transitions high before
CTRL{2,1,0} transitions to [1, 1, 1]. IQ = 400µA if Enable transitions high after CTRL{2,1,0} transitions to [1, 1, 1]. If Enable = high and CTRL{2,1,0}= [1, 1,
1] is to be used for an extended period of time, it is recommended that Enable = High when change to the [1, 1, 1] state to achieve the lower IQ level.
2005 Semtech Corp.
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SC604A
POWER MANAGEMENT
Applications Information
Designing for Lowest Possible Battery Current
The SC604A efficiency and battery current are shown in
the plots that follow on page 8. For this example, 4 LEDs
are matched at 15mA each. The battery current remains
low at 63mA well into the Li-Ion battery range as indicated
in the plot by a boundary box. The SC604A uses 1x mode
(IIN=IOUT+IQ) for part of the input voltage range, conserving
significant energy from the battery. A similar four (4)
output device uses only 1.5x mode (IIN= IOUT 1.5+IQ)
over the input voltage range. This means that the
SC604A will have about 25% higher efficiency than a
1.5x only charge pump. Where the competition drops
off at 3V, the SC604A uses 2x mode to extend the
operating range down to a battery voltage of only 2.85V.
Detailed Description
The SC604A contains a fractional charge pump, mode
selection circuit, output selection logic, current setting
detection circuit, and four current sense circuits. All are
depicted in the block diagram on page 6.
The fractional charge pump multiplies the input voltage
a multiple of 1, 1.5 or 2 times the input voltage. The
charge pump switches at a fixed 250kHz whenever the
mode is 1.5x or 2x. The charge pump does not switch
during 1x mode, saving power and improving efficiency.
The mode selection circuit automatically selects the mode
as 1x, 1.5x or 2x based on circuit conditions such as LED
voltage, input voltage and load current. 1x is the most
efficient mode, followed by 1.5x and 2x modes. At lower
voltages a stronger mode may be needed to maintain
regulation, if so, the mode will change first to 1.5x and
then to 2x. 2x mode usually operates for a much shorter
run time compared to 1x mode, and 2x mode maintains
the output until the battery is discharged to 2.85V or
less. The LED requiring the highest voltage drop will
determine the output voltage needed to drive all outputs
with adequate bias. Comparing all cathodes and
regulating VOUT for the LED with the lowest cathode
voltage ensures sufficient bias for all LEDs.
The input voltages at which the mode transitions occur
are dependent on the forward voltage VF of the LED used
and the LED current ILED. To keep the battery current low
and in the 1x mode for as long as possible, it is best to
choose an LED with a lower VF.
The mode transition voltages VTRANS1X and VTRANS1.5X can
be estimated by the following equations:
VTRANS1X = VF + VILED + [(# of LEDs used) ILED 1.2]
Output selection logic enables control over the LED
outputs for on and off functions with eight (8) different
output states. The states are defined in Table 1 on page
6.
VTRANS1.5X = VF + VILED + [(# of LEDs used) ILED 16]
1.5
The current set and detection circuit uses an external
resistor and a 1.22V reference to program the LED
current.
where, VF is the forward LED voltage measured from
anode to cathode, VILED is the voltage at the ILED pin,
typically VILED = 100mV, ILED is the LED current.
Four (4) current regulating circuits sink matched currents
from the LEDs. LEDs with matched forward voltage will
produce the best possible matched currents. For best
matching performance it is recommended that the ∆Vf
between LEDs be under 250mV. (For more information
on ∆Vf considerations refer to Semtech application
notes).
Power efficiency can now be estimated for comparison
with the intended battery voltage range.
Efficiency [%] =
VOUT IOUT
100%
VIN (IOUT Mode + IQ
(
2005 Semtech Corp.
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7
SC604A
POWER MANAGEMENT
Battery Current Comparison for 4 LEDs at 15mA Each with LED = 3.5V
110
100
Battery Current [mA]
Competition 1.5x mode
Semtech 1.5x mode
90
80
70
Semtech 1x mode
60
90% of Li-Ion battery life
50
4.2
4.1
4.0
3.9
3.8
3.7
VIN [V]
3.6
3.5
3.4
3.3
3.2
Efficiency Comparison for 4 LEDs with 15mA Each and LED = 3.5V
100
Semtech 1x mode
90
Efficiency [%]
80
Semtech 1.5x mode
70
Competition 1.5x mode
60
50
90% of Li-Ion battery life
40
4.2
4.1
4.0
3.9
3.8
3.7
3.6
3.5
3.4
3.3
3.2
VIN [V]
2005 Semtech Corp.
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SC604A
POWER MANAGEMENT
Methods for Setting LED Current
Table 2 - Resistor Value Selection
There are four methods for setting and adjusting the LED current
outlined here. The methods are:
RSET Value
1) RSET only
2) Analog Reference VADJ
3) NMOS switched parallel resistors
4) PWM Input
Method 1. The most basic means of setting the LED current is
with a resistor connected from ISET to GND, as shown in the
application circuit on Page 1. The resistor RSET establishes the
reference current needed for a constant LED current. Values of
RSET for a fixed LED current are given in Table 2 and also in the
below graph, “Typical RSET Resistance vs. LED Current”. Methods
2 and 3 on page 10 are for setting the LED current allow for
brightness control.
ILED[mA]
[kΩ]
RSET[k
N earest kΩ
Standard
Value
Standard
Value
% Difference
0.5
931
931
0.0%
1
471
470
-0.2%
2
237
237
0.0%
3
155
154
-0.6%
5
94.0
93.1
-1.0%
10
47.5
47.5
0.0%
15
31.83
31.6
-0.7%
20
24.0
24.0
0.0%
30
16.5
16.5
0.0%
Typical R SET Resistance vs. LED Current
1000
950
900
850
800
750
R SET Resistance [kΩ]
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
LED Current [mA]
2005 Semtech Corp.
6.5
7
7.5
8
8.5
9
9.5
10
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9
SC604A
POWER MANAGEMENT
Methods for Setting LED Current (Cont.)
Method 2. The example circuit in Figure 1 uses a 16.5kΩ resistor
and an analog input DC voltage, VADJ , which varies from 1.2V to 0V
to control LED current from 1mA to 30mA. Table 3 shows the
resulting output. If necessary, the analog VADJ voltage can be
sourced from a voltage higher than 1.2V, but the source must be
divided down so that the VADJ mode will not exceed 1.2V. For lower
current applications and for higher resolution, a larger resistor
may be substituted in this circuit. PWM applications are also
possible with this circuit by application of RC filtering. (Consult
with Semtech for detailed application support).
Method 3. The circuit in Figure 2 uses open drain NMOS transistors
to set an equivalent resistance for RSET. Parallel combinations are
switched on and off for R1, R2 and R3. R4 is always connected,
so that a minimum value of LED current can be maintained at
1.5mA.
Figure 1 - Analog Voltage for LED Current Control
Figure 2 - 3 Bit LED Current Control with Open Drain
Table 3 - Analog Voltage for LED Current Control
VADJ [V]
ILED [mA]
VADJ [V]
ILED [mA]
0.000
30.2
0.600
14.8
0.100
27.7
0.700
12.3
0.200
25.1
0.800
9.7
0.300
22.5
0.900
7.1
0.400
20.0
1.000
2.1
0.500
17.3
1.150
1.0
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SC604A
POWER MANAGEMENT
Methods for Setting LED Current (Cont.)
Figure 3 - PWM Example Circuit
Method 4. LED current may also be controlled by applying a PWM
signal to any of the CTRL2, CTRL1 and CTRL0 inputs. The circuit in
Figure 3 turns 4 LEDs on and off by applying a PWM signal to the
CTRL0 input. This circuit uses resistor RSET to set the on state
current and the average LED current is then proportional to the
percentage of on-time when the CTRL0 pin is a logic low. Average
LED current is approximately equal to:
IAVG = (tON ILED_ON)/(tON + tOFF)
The recommended PWM frequency is between 100Hz and 500Hz.
Due to start up delay and ramp up time, frequency >500Hz will
result in error in the average value of ILED. Frequency <100Hz can
naturally cause the LEDs to blink visibly.
In PWM applications where ILED4 is not used, keep ILED4 pin 13
open. Connecting ILED4 to ground can result in the charge pump
operating in open loop mode. Connecting ILED4 to VIN will work
but will cause shutdown current IQ to increase to approximately
VIN / 100k.
Table 4 - Summary of LED Current Control
LED Current Control Method
Figure of Reference
LED Current Range
Brightness
Control
Method 1
RSET Only
Circuit on Page 1
0.5mA < ILED < 30mA
Fixed Brightness
Method 2
Analog Reference VADJ
Figure 1 on Page 10
0.5mA < ILED < 30mA
In f i n i t e
Method 3
NMOS Switched Parallel
Resistors
Figure 2 on Page 10
0.5mA < ILED < 30mA
2N Stepped
Current Levels(1)
Method 4
PWM CTRLx Input(s)
Figure 3 on page 11
0.5mA < ILED < 30mA
In f i n i t e
Note: 1) “N” is the number of NMOS transistors used for brightness control.
2005 Semtech Corp.
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11
SC604A
POWER MANAGEMENT
Typical Characteristics
Startup with 4 LEDs at 20 mA
OVP Event with LED Open Circuit
Efficiency vs. Load at High Battery
Efficiency vs. Load at Low Battery
100
100
VIN = 3.4V
VIN = 3.8V
VIN = 4.0V
90
VIN = 4.2V
Efficiency [%]
Efficiency [%]
90
80
70
60
80
VIN = 2.8V
70
60
50
50
0
20
40
60
80
100
120
0
Total Load Current [mA]
20
Mode Transition Voltage vs. LED Voltage
3.9
40
60
80
Total Load Current [mA]
100
120
Quiescent Current Trend
5
1X to 1.5X Mode for 4 LEDs
3.8
Quiescent Current [mA]
Vf = 3.6V
Input Voltage [V]
VIN = 3.6V
3.7
3.6
Vf = 3.4V
3.5
3.4
Vf = 3.2V
3.3
3.2
4
3
Trend for 4 LEDs
2
1
0
0
5
10
15
20
25
30
35
LED Current [mA]
0
20
40
60
80
100
120
Total Output Current [mA]
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SC604A
POWER MANAGEMENT
Typical Characteristics with 4 LEDs
Efficiency for 4 LEDs at 20mA
Battery Current for 4 LEDs at 20mA
100
140
LED = 3.45V
90
120
Efficiency [%]
Battery Current [mA]
LED = 3.45V
100
80
60
80
70
60
40
50
4.2
4.0
3.8
3.6
3.4
3.2
4.2
Input Voltage [V]
Battery Current for 4 LEDs at 10mA
4
3.8
3.6
Input Voltage [V]
3.4
3.2
3.4
3.2
3.4
3.2
Efficiency for 4 LEDs at 10mA
80
100
LED = 3.37V
90
LED = 3.37V
Efficiency [%]
Battery Current [mA]
70
60
50
40
80
70
60
30
50
4.2
4
3.8
3.6
Input Voltage [V]
3.4
3.2
4.2
4
3.8
3.6
Input Voltage [V]
Efficiency for 4 LEDs at 0.5mA
Battery Current for 4 LEDs at 0.5mA
4
70
3.5
60
LED = 2.91V
Efficiency [%]
Battery Current [mA]
LED = 2.91V
3
2.5
50
40
30
2
20
1.5
4.2
4
3.8
3.6
Input Voltage [V]
3.4
3.2
2005 Semtech Corp.
4.2
4
3.8
3.6
Input Voltage [V]
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13
SC604A
POWER MANAGEMENT
Typical Characteristics with 4 LEDs
Ripple in 1x Mode for 4 LEDs at 20mA Each
Ripple in 1.5x Mode for 4 LEDs at 20mA Each
Ripple in 2x Mode for 4 LEDs at 20mA Each
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14
NEG
GND
1
BATTERY -
VBAT 1
BATTERY +
1
1
2
C6
10uF
VBAT
LED1
LED2
LED3
LED4
GND
0.22
RIN
1
1
1
1
1
BATTERY -
1
R4-
R4+
2
1
1
Input Resistance By pass
1
2
JP5
D4
R4
1ohm
D3
R3
1ohm
2
9
GND
C2+
C2-
C1-
D2
R2
1ohm
R1
1ohm
JP1
1
D1
EN
CTRL0
CTRL1
J1
R1-
R1+
1
SC604
CRTL2
JP2
1
1
12
C2+ 11
C2- 10
C1-
C1+
J2
R2-
R2+
1.0uF
C2
2
1.0uF
C1
JP3
1
1
J3
1
1
1
C2+
1
C2-
1
C1-
1
C1+
3
POT_3296W-105
1M
JP4
R3-
R3+
C4
1.0uF
1
2
J4
1
2
1
2
JP7
Connect RSET pot.
TBD
1
2
RSET
1
1
JP6
ON
3 OFF
2
1
VOUT
ENABLE
CNTRL0
2
CNTRL2
VOUT
CNTRL1
ENABLE
C3
1.0uF
3
4
1
2
CTRL2
VBAT
HIGH
1
1
2
POS
RSET
2
1
CTRL1
HIGH
LOW
3
Input Jacks
J5
2
2
1
2
1
1
16.5k
2
2
1
2
2
2
1
8
C1+
ILED4
13
1
2
2
ILED3
14
5
2
1
2
15
1
2
2
7
VIN
6
VOUT
ILED2
ISET
ILED1
16
2
1
2
2
CTRL0
HIGH
LOW
3
RADJ
2
15
1
2005 Semtech Corp.
1
1
1
2
Analog Control
LOW
3
VADJ 1
SC604A
POWER MANAGEMENT
Evaluation Board Schematic
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SC604A
POWER MANAGEMENT
Evaluation Board Bill of Materials
Reference
Value
Comment
U1
C1,C2,C3,C4
C6
D1,D2,D3,D4
J1, J2, J3, J4
JP1,JP2,JP3,JP4
JP5
JP6
JP7
CTRL0,CTRL1,CTRL2
RSET
SC604A
1.OµF
10µF
3296W-105
0.22Ω
16.5kΩ
-
Component references in bold are the only essential design components.
Bucket, input and output capacitors. Ceramic, low ESR type, 6.3V rating or higher.
This extra capacitor supports usage of long power leads from benchtop supply.
Add LEDs to meet the requirements of the application.
Jumpers in series with each LED.
Jumpers to bypass each 1Ω sense resistor and bypass J1, J2, J3 and J4.
Jumper for bypassing the R4 input resistor.
Enable jumper.
Connects RSET potentiometer. Remove this jumper when using a fixed value R1.
Jumpers provide High/Low settings for the control bits.
RSET resistor
Evaluation board has 1MΩ potentiometer in place of R1.
Series input resistor for studying effects of input resistance.
Resistor for analog brightness control. Apply test signal of 0 to 1.2V at VADJ test point.
Banana jacks for power supply.
R4
RADJ
J5
Evaluation Board Gerber Plots
Bottom View
Top View
2005 Semtech Corp.
16
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SC604A
POWER MANAGEMENT
Outline Drawing- MLP-16 [4x4]
A
DIMENSIONS
INCHES
MILLIMETERS
DIM
MIN NOM MAX MIN NOM MAX
D
A
A1
A2
b
D
D1
E
E1
e
L
N
aaa
bbb
B
PIN 1
INDICATOR
(LASER MARK)
E
A2
A
aaa C
A1
C
.031
.040
.000
.002
(.008)
.010 .012 .014
.153 .157 .161
.074 .085 .089
.153 .157 .161
.074 .085 .089
.026 BSC
.018 .022 .026
16
.003
.004
0.80
1.00
0.00
0.05
(0.20)
0.25 0.30 0.35
3.90 4.00 4.10
1.90 2.15 2.25
3.90 4.00 4.10
1.90 2.15 2.25
0.65 BSC
0.45 0.55 0.65
16
0.08
0.10
SEATING
PLANE
D1
e/2
N
LxN
E/2
E1
2
1
e
D/2
bxN
bbb
C A B
NOTES:
1.
CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
2.
COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS.
Marking Information
604A
yyww
yyww = Datecode (Example: 0452)
2005 Semtech Corp.
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17
SC604A
POWER MANAGEMENT
Land Pattern MLP-16pin [4x4]
K
DIM
2x (C)
H
2x G
2x Z
Y
X
C
G
H
K
P
X
Y
Z
DIMENSIONS
INCHES
MILLIMETERS
(.148)
.106
.091
.091
.026
.016
.041
.189
(3.75)
2.70
2.30
2.30
0.65
0.40
1.05
4.80
P
NOTES:
1.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805) 498-2111 FAX (805)498-3804
Visit us at: www.semtech.com
2005 Semtech Corp.
www.semtech.com
18