SEMTECH SC2608STRT

SC2608
Simple, Synchronous
Voltage Mode PWM Controller
POWER MANAGEMENT
Description
Features
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SC2608 features include temperature compensated volt- ‹
age reference, triangle wave oscillator, current limit com- ‹
parator, and an externally compensated error amplifier. ‹
The SC2608 is a versatile voltage-mode PWM controller
designed for use in step down DC/DC power supply applications. A simple, fixed frequency, highly efficient buck
regulator can be implemented using the SC2608 with minimal external components. The input voltage range is from
+3.3V to +12V. Internal level shift and drive circuitry eliminates the need for an expensive P-channel, high-side
MOSFET. The small device footprint allows for compact
circuit design.
Current limit is implemented by sensing the voltage drop
across the bottom MOSFET RDS(ON).
+3.3V or +5V or +12V input voltage
200kHz operation
High efficiency (>90%)
1% Reference voltage accuracy
Hiccup mode over current protection
Robust output drive
RDS(ON) Current sensing for protection
Industrial temperature range
SO-8 package
Integrated boot strap diode
Thermal Shut down
Fully WEEE and RoHS Compliant
Applications
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The SC2608 operates at a fixed frequency of 200kHz
providing an optimum compromise between efficiency ,
external component size, and cost.
SC2608 has a thermal protection circuit, which is
activated if the junction temperature exceeds 150 OC.
Termination supplies
Low cost microprocessor supplies
Peripheral card supplies
Industrial power supplies
High density DC/DC conversion
Typical Application Circuit
SC2608
sense
COMP/SS SENSE
+12V/+5V/+3.3V
+12V
GND
VCC
DL
PHASE
DH
BST
VOUT
sense
Figure 1
Revision 4: October, 2005
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SC2608
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.
P a r a met er
M a xi m u m
Un i ts
VCC to GND
+20
V
BST to PHASE
+15
V
BST to GND
+35
V
-1 to +24
V
+15
V
-1 to +15
V
COMP/SS to GND
+7
V
SENSE to GND
+7
V
PHASE to GND
Symb ol
(note1)
DH to PHASE
DL to GND
(note1)
Thermal Resistance Junction to Case
θJC
40
O
C/W
Thermal Resistance Junction to Ambient
θJA
163
O
C/W
Operating Temperature Range
TJ
-40 to +125
O
C
Storage Temperature Range
TSTG
-65 to +150
O
C
ESD Rating (Human Body Model)
ESD
2
kV
Note 1: Under pulsing condition, the peak negative voltage can not be lower than -3.6V.
Electrical Characteristics
Unless specified: VCC = 12V, VBST - VPhase = 12 V, VOUT = 3.3V, TJ = TA = 25oC.
P a r a met er
Symb ol
C on d i t i on s
Mi n
Ty p
Ma x
Un i ts
14
V
P ower Su p p l y
Supply Voltage
VCC
Supply Current
IC C
4.5
VCOMP < 0.4V
6
mA
E r r or A mp l i f i er
E/A Transconductance
Gm
7
mS
Open Loop DC Gain
AO
60
dB
Input Bias Current
IFB
1
Output Sink Current
ISINK
VSENSE > 0.9V; VCOMP = 2.1V
-700
uA
Output Source Current
ISOURCE
VSENSE < 0.7V; VCOMP = 2.1V
120
uA
3
uA
O sci l l a t or
Switching Frequency
© 2005 Semtech Corp.
FOSC
Vcc =12V
2
180
200
220
kHz
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SC2608
POWER MANAGEMENT
Electrical Characteristics
Unless specified: VCC = 12V, VBST - VPhase = 12 V, VOUT = 3.3V, TJ = TA = 25oC.
P a r a met er
Symb ol
C on d i t i on s
Mi n
Ty p
Ma x
Un i ts
Ramp Peak Voltage
VP-K
4.75V < VCC < 12.6V
1.8
V
Ramp Valley Voltage
VV
4.75V < VCC < 12.6V
0.8
V
Maximum Duty Cycle
DMAX
200kHz
90
%
DH Sink/Source Current
ID H
tPW > 400nS
VGS = 4.5V (src)
0.6
0.8
A
DL Sink/Source Current
ID L
VGS = 2.5V (snk)
0.6
0.7
DH Rise/Fall Time
tr, tf
CL = 3000pF, See Fig. 2
50
ns
DL Rise/Fall Time
tr, tf
CL = 4000pF, See Fig. 2
50
ns
Dead Time
tdt
See Fig. 2
80
ns
DL Minimum On Time
tON
4.75V < Vcc < 12.6V
400
ns
Reference Voltage
VREF
VCC = 12V
0 .7 9 2
Temp Variance
∆VREF
-40 < TJ < +125 OC
-1.5
Line Variance
∆VREF
4.75V < VCC <12.6V
VTRIP
4.75V < Vcc < 12.6V
Vtrip = VPHASE - GND
SS Source Current
ISRC
VCOMP < 2.5V
1.5
uA
SS Sink Current
ISNK
VCOMP > 0.5V
-1.5
uA
UVLO Threshold
Vth
-40< TJ < 85OC
UVLO Hysterisis
Vhys
-40< TJ < 85OC
M O SF E T D r i v er s
A
Ref er en ce Sect i on
0.8
0.808
V
1.5
%
4
mV
-130
mV
C u r r en t L i mi t
Trip Voltage
-190
-160
Sof t - St a r t
U n d er v ol t a g e L ock ou t
4.1
4.3
200
4.5
V
mV
T h er ma l Sh u t d own
Over Temperature Trip Point
© 2005 Semtech Corp.
150
TOTP
3
C
o
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SC2608
POWER MANAGEMENT
Gate Drive Timing Diagram
Figure 2
Block Diagram
BST
VCC
LEVEL
SHIFT
OSC
DH
S
REF
0.8V
+
E/A
R
-
+
SENSE
PHASE
PWM
-
NON-OVERLAP
TIMING
Q
0
VCC
Vcc
OCP &
UVLO
DL
OCP
0
+
-
GND
PHASE
0
0
COMP/SS
Figure 3
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SC2608
POWER MANAGEMENT
Pin Configuration
Ordering information
Top View
Device
8
BST
1
DH
2
7
COMP/SS
GND
3
6
SENSE
DL
4
5
VCC
(1)
Package
Temp Range (TJ)
SO-8
-40 to 125OC
SC2608STRT(2)
PHASE
SC2608EVB
Evaluation Board
Notes:
(1) Only available in tape and reel packaging. A reel contains 2500 devices.
(2) This device is fully WEEE and RoHS Compliant
(8-Pin SO-8)
Pin Descriptions
Pin
#
P i n N am e
1
BST
Bootstrap for high side driver.
2
DH
High side driver outp ut.
3
GN D
4
DL
Low side driver outp ut.
5
VCC
Chip bias sup p ly p in.
6
Sense
7
COMP/SS
8
PHASE
© 2005 Semtech Corp.
P i n Fu n c t i o n
Ground.
Outp ut voltage sense inp ut.
Error amp lifier outp ut. Connect comp ensation network to GN D. The comp ensation cap acitor
serves as soft star t cap acitor. By p ulling this p in low will disable the outp ut.
Connect this p in to the switching node between the MOSFETs.
5
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SC2608
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Theory of Operation
Synchr
onous Buck Con
Synchronous
Convv er
ertter
The output voltage of the synchronous converter is set and
controlled by the output of the error amplifier. The inverting input of the error amplifier receives its voltage from the
SENSE pin. The non-inverting input of the error amplifier is
connected to an internal 0.8V reference. The error amplifier output is connected to the compensation pin. The
error amplifier generates a current proportional to (Vsense
- 0.8V), which is the COMP pin output current
(Transconductance ~ 7mS). The voltage on the COMP
pin is the integral of the error amplifier current. The COMP
voltage is the non-inverting input of the PWM comparator
and controls the duty cycle of the MOSFET drivers. The
compensation network controls the stability and transient
response of the regulator. The larger the capacitor, the
slower the COMP voltage changes, and the slower the duty
cycle changes.
The non-inverting input voltage of the PWM comparator is
the triangular ramp signal generated from the oscillator.
The peak-to-peak voltage of the ramp is 1V, this is a parameter used in control loop calculation. When the oscillator ramp signal rises above the COMP voltage, the comparator output goes high and the PWM latch is reset. This
pulls DH low, turning off the high-side MOSFET. After a
short delay (dead time), DL is pulled high, turning on the
low-side MOSFET. The oscillator also produces a set pulse
for the PWM latch to turn off the low-side MOSFET, After a
delay time, DH is pulled high to turn on the high-side
MOSFET. The delay time is determined by a monostable
on the chip.
The triangle wave minimum is about 0.8V, and the maximum is about 1.8V. Thus, if Vcomp = 0.7V, high side duty
cycle is the minimum (~0%) , but if Vcomp is 1.8V, duty cycle
is at maximum ( ~90%).The internal oscillator uses an onchip capacitor and trimmed precision current sources to set
the oscillation frequency to 200kHz. Figure 1 shows a 2.5V
output converter. If the Vout <2.5V, then the SENSE voltage
< 0.8V. In this case the error amplifier will be sourcing current into the COMP pin so that COMP voltage and duty cycle
will gradually increase.If Vout > 2.5V, the error amplifier will
sink current and reduce the COMP voltage, so that duty cycle
will decrease.The circuit will be in steady state when Vout
=2.5V , Vsense = 0.8V, Icomp = 0. The COMP voltage and
duty cycle depend on Vin.
remain in the off state whenever the supply voltage drops
below the set threshold. Lockout occurs if VCC falls below
4.3V typ.
Sof
Softt Star
Startt
The SC2608 provides a soft start function to prevent large
inrush currents upon power-up or hiccup retry. If both COMP
and SENSE pins are low (<300mV), the device enters soft
start mode, and the compensation capacitor is slowly charged
by an internal 1.5uA current source. When the COMP pin
reaches 300mV, the low side FET is switched on in order to
refresh the bootstrap capacitor, and begin PWM from a known
state. As the COMP pin rises above 800mV, PWM begins at
minimum duty cycle.
COMP continues to charge, slowly sweeping the device
through the duty cycle range until FB reaches the regulation
point of 800mV. Once FB reaches the regulation point, the
soft start current is switched off, and the strong error amp is
enabled, providing a glitch-free entrance into closed loop
operation. The overcurrent comparator is still active during
soft start mode, and will override soft start in the event that
an overcurrent is detected, such as startup into a dead
short.
R DS(ON) Current Limiting
In case of a short circuit or overload, the low-side (LS) FET
will conduct large currents. To protect the regulator in this
situation, the controller will shut down the regulator and begin a soft start cycle later. While the LS driver is on,the Phase
voltage is compared to the OCP trip voltage. If the phase
voltage is lower than OCP trip voltage, an over current condition is detected. The low-side Rdson sense is implemented at
end of each LS-FET turn-on duration. The minimum turn-on
time of the LS-FET is set to be 400nS. This will ensure the
sampled signal is noise free by giving enough time for the
switching noise to die down.
OCP Hiccup
In the event that an overcurrent is detected, the SC2608
latches the fault and begins a hiccup cycle. Switching is
immediately stopped, and the drivers are set to a tristate
condition (Both DH and DL are low). COMP is slowly
discharged to 300mV with an internal 1.5uA current source,
providing a long cooldown time to keep power dissipation
low in the event of a continuous dead short. Once COMP
and SENSE both fall below the 300mV threshold, the part
U nder V
oltage Lock
out
Voltage
Lockout
re-enables the 1.5uA soft start current , and the device begins
The under voltage lockout circuit of the SC2608 assures a normal startup cycle again.
that both high-side and low-side MOSFET driver outputs
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SC2608
POWER MANAGEMENT
Applications Information (Cont.)
G pwm =
A note to the user is needed: The device cannot restart until
both COMP and SENSE are low, to prevent start up into a
charged output. In the event of an overcurrent condition,
the output is quickly discharged by the load, therefore bringing
SENSE below the 300mV threshold. If the COMP pin is pulled
low by an external device (such as an open-drain logic gate
used for system shutdown), and SENSE is high(above 300mV)
is high while COMP is low, then the SC2608 turns on the low
side FET to discharge the output before changing to shutdown
or soft-start mode. The low side FET turns off when SENSE
drops below 300mV and the converter remains in the tristate condition until COMP is released. Although this
shutdown technique can be used successfully on the SC2608,
the system designer using COMP for external shutdown will
need to consider the load on the low side FET when
discharging the output capacitor bank. For large capacitor
bank, this peak current can be quite large as it is limited only
by the RDS(ON) of the low side FET. Fortunately the duration of
this event is quite short, and has been shown in the lab to
have no detrimental effect on the performance of the external
FETs.
Disabling the output by pulling down COMP/SS pin is only
recommended when the output capacitor bank is not too
large.
VBG
G_PWM
L
R
Rc
0.8V
Ci
VIN
C
Co
V 
1 + sRcCo
T (s ) = Gm • G pwm • Vin •  bg  • H c (s ) •

 R 
L
 Vo 
1 + s RcCo +  + s 2 LCo 1 + c 
R
o 

 Ro 
H c (s ) =
1
sC
+ sC i
The task here is to properly choose the compensation network for a nicely shaped loop-gain Bode plot. The following design procedures are recommended to accomplish
the goal:
(1) Calculate the corner frequency of the output filter:
Fo =
2π
1
LC o
(2) Calculate the ESR zero frequency of the output filter
capacitor:
Fesr =
1
2π R c C o
(3) Check that the ESR zero frequency is not too high.
F esr <
F SW
5
If this condition is not met, the compensation structure
may not provide loop stability. The solution is to add some
electrolytic capacitors to the output capacitor bank to correct the output filter corner frequency and the ESR zero
frequency. In some cases, the filter inductance may also
need to be adjusted to shift the filter corner frequency. It
is not recommended to use only high frequency multi-layer
ceramic capacitors for output filter.
(4) Choose the loop gain cross over frequency (0 dB frequency). It is recommended that the crossover frequency
is always less than one fifth of the switching frequency :
1
FX _ OVER = • FSW
5
If the transient specification is not stringent, it is better to
choose a crossover frequency that is less than one tenth of
the switching frequency for good noise immunity. The
resistor in the compensation network can then be calculated as:
R1
Ro
R2
The control model of SC2608 is depicted in Fig. 4. This
model can also be used to generate loop gain Bode plots.
The bandgap reference is 0.8V and trimmed to +/-1%
accuracy. The desired output voltage can be achieved by
setting the resistive divider network, R1 and R2. The error
amplifier is transconductance type with fixed gain of:
2
0 . 007 A
V
The compensation network includes a resistor and a capacitor in series, which terminates the output of the error
amplifier to the ground.
The PWM gain is inversion of the ramp amplitude, and
this gain is given by:
© 2005 Semtech Corp.
1
1
R+
Fig. 4. SC2608 small signal model.
Gm =
Vramp
where the ramp amplitude is fixed at 1 volts.
The total control loop-gain can then be derived as
follows:
Compensation Network Design
E/A
1
when
 V 
F  F
1
R=
•  esr  •  X _ OVER  •  o 
Gpwm •Vin • Gm  Fo   Fesr   Vbg 
F o < F esr <
7
F sw
5
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SC2608
POWER MANAGEMENT
Applications Information (Cont.)
An example is given below to demonstrate the procedure
introduced above.
(5) The compensation capacitor is determined by choosing
the compensator zero to be about one fifth of the output
filter corner frequency:
F zero
C=
Co=4400uF
Rc=0.009Ω
Vbg=0.8V
Vramp=1V
Gm=0.007A/V
Vin=12V
Vo=2.5V
Io=15A
Fsw=200KHz
L=2.2uH
F
= o
5
1
2πR • Fzero
SC2608 soft start time is determined by the
compensation capacitor. Capacitance can be adjusted to
satisfy the soft start requirement.
set
(6) The final step is to generate the Bode plot by using the
simulation model in Fig. 4 or using the equations provided
here with Mathcad. The phase margin can then be
checked using the Bode plot.
Ci=1nF
Rc=1.33KΩ
set to Rc=1.5KΩ
C=327.95nF
set to C=100nF
for suitable soft start time
Loop Gain Mag (dB)
100
50
mag( i)
0
50
10
100
1 .10
3
4
Fi
1 .10
1 .10
5
1 .10
5
1 .10
6
Loop Gain Phase (Degree)
0
45
phase ( i)
90
135
180
10
100
1 .10
3
4
Fi
1 .10
1 .10
6
Fig. 5. Bode plot of the loop
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SC2608
POWER MANAGEMENT
Typical Performance Characteristics
Frequency vs. Temperature
0.83
210
0.82
200
Frequency(KHz)
Vref(V)
Vref vs. Temperature
0.81
0.80
0.79
190
180
170
-50
-25
0
25
50
75
100
125
-50
-25
0
25
180
4.40
170
4.20
150
4.10
0
25
50
75
100
-50
125
-25
0
25
50
75
100
125
Icc vs. Temperature
Gate driver dead time vs. Temperature
100
4.0
90
3.7
Icc(mA)
Gate driver dead time(ns)
125
Temperarure(℃)
Temperature(℃)
80
70
3.4
3.1
60
2.8
-50
-25
0
25
50
75
100
125
-50
-25
0
Temperature(℃)
25
50
75
100
125
Temperature(℃)
Soft start sourcing vs. Temperature
UVLO_Hysteresis vs. Temperature
1.65
200
UVLO_Hysteresis(mV)
Soft start souring current(uA)
100
4.30
160
-25
75
UVLO vs. Temperature
4.50
UVLO(V)
I_limit trip(mV)
I_limit vs. Temperature
190
-50
50
Temperature(℃)
Temperature(℃)
1.55
1.45
1.35
1.25
150
100
50
0
-50
-25
0
25
50
75
100
125
-50
Temperature(℃ )
© 2005 Semtech Corp.
-25
0
25
50
75
100
125
Temperature(℃ )
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SC2608
POWER MANAGEMENT
Application Information
TTypical
ypical Application Schematic
C1
C2
C3
1 5 00 u F /1 6 V
1 5 00 u F /1 6 V
IP B 09N 03LA
Q1
4 .7 u F /1 6 V
+12V/+5V/+3.3V
C13
1uF/16V
DL
3
4
SC2608
L1 1.2uH
R4
1R
C12
2.2nF
C7
C8
C9
C10 C11
4.7uF /6.3V
VCC
Q2
4.7uF /6.3V
R5
1R
SENSE GND
C5
1uF/16V
4.7uF /6.3V
5
+12V
COMP/SS DH
2
2200uF /6.3V
6
BST
1.6VOUT/20A
2200uF /6.3V
R2 1.5k C6 100n
Phase
1
IP D 06N 03LA
8
7
Sense
R1 2R2
U1
C4
1n
R3
1K
Sense
R6
1K
VOUT = 0.8V X (R3+R6)/R6
Bill of Materials
Item
Qu an ti ty
Referen ce
Par t
Ven d er
1
1
C1
4.7u F/16V
A ny
2
2
C2,C3
1500u F/16V
Pan ason i c FJ
3
1
C4
1n F/50V
A ny
4
2
C5,C13
1u F/16V
A ny
5
1
C6
100n F/25V
A ny
6
2
C7,C8
2200u F/6.3V
Pan ason i c FJ
7
3
C9,C10,C11
4.7u F/6.3V
A ny
8
1
C12
2.2n F
A ny
9
1
L1
1.2u H
A ny
10
1
Q1
IPD09N 03LA
In fi n eon
11
1
Q2
IPD06N 03LA
In fi n eon
12
1
R1
2R2
A ny
13
1
R2
1.5K
A ny
14
2
R3,R6
1K, 1%
A ny
15
2
R4,R5
1R0
A ny
16
1
U1
SC2608
SEMTECH
© 2005 Semtech Corp.
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POWER MANAGEMENT
Typical Performance Characteristics
Start up
Effic ie nc y V.S . Loa d C urre nt
92
Vin
90
Efficiency (%)
88
Comp/ ss
86
84
DL
82
80
VOUT
78
1
2
3
4
5
6
7
8
9
10 11 12 13 14 15 16 17 18 19 20
Loa d C urre nt (A)
Over Current Protection (33A DC tripped)
Transient Response
VIN
COMP/SS
VOUT
Comp/ss
DH
IL (10A/10mV)
VOUT
0 -18 A step load
OCP HICCUP
Gate waveforms
VIN
DH
Comp/SS
Phase node
DH
DL
VOUT
15 A sustain loading
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Application Information
TTypical
ypical DDR VDDQ Application Schematic
D2
D1N4148
C15
1uF/16V
4
SC2608
C8
C9
C10
C11
R4
2R2
C14
1n
C12 C13
4.7uF /6.3V
3
L1
1.2uH/40A
1.8VOUT/24A
4.7uF /6.3V
DL
Q2
4.7uF /6.3V
VCC
C6
1uF/16V
1800uF /6.3V
D1
BAT54H
SENSE GND
2
1500uF /6.3V
5
COMP/SS DH
1800uF /6.3V
6
BST
1
1500uF /6.3V
5VDual
Sense
Phase
C4
1800uF /6.3V
R2
5.1k
7
C3
IP D 06N 03LA
C7
220nF
U1
8
C2
1500uF /6.3V
R1
2.2R
C5
330pF
C1
IP D 06N 03 LA
Q1
4.7uF /16V
5VDual
R3
1.27k
Sense
R5
1k
+12V
Bill of Materials
Item
Qu an ti ty
Referen ce
Par t
Ven d er
1
4
C1,C11,C12,C13
4.7u F/6.3V
A ny
2
3
C2,C3,C4
1500u F/6.3V
Pan ason i c FJ
3
1
C5
330p F/50V
A ny
4
2
C6,C15
1u F/16V
A ny
5
1
C7
220n F/25V
A ny
6
3
C8,C9,C10
1800u F/6.3V
Pan ason i c FJ
7
1
C14
1n F/50V
A ny
8
1
D1
B AT54H
A ny
9
1
D2
1N 4148
A ny
10
1
L1
1.2u H/40A
A ny
11
1
Q1
IPD06N 03LA
In fi n eon
12
1
Q2
IPD06N 03LA
In fi n eon
13
2
R1,R4
2R2
A ny
14
1
R2
5.1K
A ny
15
1
R3
1.27K, 1%
A ny
16
1
R5
1K, 1%
A ny
17
1
U1
SC2608
SEMTECH
© 2005 Semtech Corp.
12
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SC2608
POWER MANAGEMENT
Application Information
TTypical
ypical High In
put V
oltage Application Schematic
Input
Voltage
20VIN
R6 1KR/1206
1KR/1206
R7
5
D1
8.2V
SENSE GND
VCC
C11
1uF/16V
DL
2
3
4
C10
2.2nF
SC2608
4.7uF/25V
L1
5VOUT/8A
2.2uH
Q2
R4
2R2
C9
1n
C6
C7
C8
4.7uF/6.3V
Vin
6
COMP/SS DH
C4
1uF/16V
4.7uF/6.3V
Sense
C5 100n
BST
C2
2200uF/6.3V
1K
Phase
1
IPD13N03LA
8
7
R3
R2 5R1
U1
C3
10pF/Opt.
C1
1000uF/25V
R1 0R
IPD13N03LA
Q1
R5
5.25K
Sense
R7
1k
Bill of Materials
Item
Q ua nti ty
Refer ence
Pa r t
Vender
1
1
C1
4.7uF/25V
A ny
2
1
C2
1000uF/25V
Pa na soni c FJ
3
1
C3
10pF/50V , O pt.
A ny
4
2
C 4,C 11
1uF/16V
A ny
5
1
C5
100nF/16V
A ny
6
1
C6
2200uF/6.3V
Pa na soni c FJ
7
2
C 7,C 8
4.7uF/6.3V
A ny
8
1
C9
1nF/50V
A ny
9
1
C 10
2.2nF/50V
A ny
10
1
D1
Zener 8.2V
A ny
11
1
L1
2.2uH/15A
A ny
12
1
Q1
IPD13N03LA
Infi neon
13
1
Q2
IPD13N03LA
Infi neon
14
1
R1
0R
A ny
15
1
R2
5.1R
A ny
16
2
R3,R7
1 .K , 1 %
A ny
17
1
R4
2R2
A ny
18
1
R5
5.25K , 1%
A ny
19
2
R6,R7
1K R, 1206
A ny
20
1
U1
SC 2608
SEMTEC H
© 2005 Semtech Corp.
13
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SC2608
POWER MANAGEMENT
Outline Drawing - SO-8
A
D
e
N
D IM
E1
1
E
2
ccc C
2 X N /2 T IP S
.0 6 9
.0 1 0
.0 6 5
.0 2 0
.0 1 0
.1 9 7
.1 9 3
.1 5 7
.1 5 4
.2 3 6 B S C
.0 5 0 B S C
.0 1 0
.0 2 0
.0 4 1
.0 2 8
.0 1 6
(.0 4 1 )
8
8
0
.0 0 4
.0 1 0
.0 0 8
.0 5 3
.0 0 4
.0 4 9
.0 1 2
.0 0 7
.1 8 9
.1 5 0
A
A1
A2
b
c
D
E1
E
e
h
L
L1
N
01
aaa
bbb
ccc
2 X E /2
e /2
B
D
D IM E N S IO N S
M IL L IM E T E R S
IN C H E S
M IN N O M M A X M IN N O M M A X
aaa C
A2
S E A T IN G
PLANE
C
h
A
A1
bxN
bbb
1 .7 5
0 .2 5
1 .6 5
0 .5 1
0 .2 5
5 .0 0
4 .9 0
4 .0 0
3 .9 0
6 .0 0 B S C
1 .2 7 B S C
0 .2 5
0 .5 0
0 .4 0
1 .0 4
0 .7 2
(1 .0 4 )
8
0
8
0 .1 0
0 .2 5
0 .2 0
1 .3 5
0 .1 0
1 .2 5
0 .3 1
0 .1 7
4 .8 0
3 .8 0
h
H
C A -B D
c
GAGE
P LA N E
0 .2 5
S E E D E T A IL
A
S ID E V IE W
L
(L 1 )
D E T A IL
01
A
NO TES:
1.
C O N T R O L L IN G D IM E N S IO N S A R E IN M IL L IM E T E R S (A N G L E S IN D E G R E E S ).
2.
DATUM S
3.
D IM E N S IO N S "E 1 " A N D "D " D O N O T IN C L U D E M O L D F L A S H , P R O T R U S IO N S
OR GATE BURRS.
© 2005 Semtech Corp.
-A -
AND
-B -
T O B E D E T E R M IN E D A T D A T U M P L A N E -H -
14
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SC2608
POWER MANAGEMENT
Land Pattern - SO-8
X
DIM
(C)
G
Z
Y
C
G
P
X
Y
Z
DIMENSIONS
INCHES
MILLIMETERS
(.205)
.118
.050
.024
.087
.291
(5.20)
3.00
1.27
0.60
2.20
7.40
P
NOTES:
1.
THIS LAND PATTERN IS FOR REFERENCE PURPOSES ONLY.
CONSULT YOUR MANUFACTURING GROUP TO ENSURE YOUR
COMPANY'S MANUFACTURING GUIDELINES ARE MET.
2. REFERENCE IPC-SM-782A, RLP NO. 300A.
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805)498-2111 FAX (805)498-3804
© 2005 Semtech Corp.
15
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