2A EcoSpeed
®
Step-Down Regulator
with LDO and Power Save
POWER MANAGEMENT
Features
SC410A
Description
The SC410A is an integrated, synchronous 2A EcoSpeed
®
step-down regulator. It incorporates Semtech’s advanced,
patented adaptive on-time architecture to achieve best-
in-class dynamic performance using point-of-load appli-
cations. The input voltage range is 7V to 24V with a
programmable output voltage from 0.75V up to 7.5V. The
device features an internal LDO and PSAVE mode for high
efficiency across the output load range.
Adaptive on-time control provides programmable
pseudo-fixed frequency operation in continuous conduc-
tion and excellent transient performance. The switching
frequency can be set from 200kHz to 1MHz, allowing the
designer to reduce external LC filtering and minimize light
load (standby) losses.
Additional features include cycle-by-cycle current limit,
soft start, output OV protection and over temperature
protection. The open-drain PGOOD pin provides output
status.
The device is available in a low profile, thermally enhanced
MLPD 3 x 3(mm) 10-pin package.
Input voltage — 7V to 24V
Output voltage — 0.75V to 7.5V
Output current — Up to 2A
Internal reference — + 1%
Small ceramic capacitors
Power good pin (open-drain)
Adaptive on-time control:
Excellent transient response
Programmable pseudo-fixed frequency during
CCM
Fault protection features (automatic fault recovery):
Cycle-by-cycle current limit
Short circuit protection
Over and under output voltage protection
Over-temperature
Internal soft-start
Power save and smart PSAVE
Internal LDO for bias voltage
Ultra-small lead-free 3 x 3(mm), 10-Pin MLPD package
WEEE and RoHS compliant and halogen-free
•
•
•
•
•
•
Applications
Networking Equipment, Embedded Systems
Medical Equipment, Office Automation
Instrumentation, Portable Systems
Consumer Devices such as DTV and Set-top Boxes
POL Converters
Typical Application Circuit
Enable
V
IN
EN
VIN
TON
C
IN
R
TON
LDO
C
LDO1
AGND
FB
PGND
R
BOT
SC410A
PGOOD
BST
LX
C
BST
PGOOD
L1
C
OUT
R
TOP
V
OUT
C
LDO2
Rev. 1.0
© 2011 Semtech Corporation
1
SC410A
Pin Configuration
Ordering Information
Device
SC410AMLTRT
(1)(2)
SC410AEVB
BST
VIN
LX
PGND
PGOOD
1
2
3
4
5
TOP VIEW
10
9
8
7
6
LDO
AGND
TON
EN
FB
Package
MLPD-10 3 x 3
Evaluation Board
Notes:
(1) Available in tape and reel only. A reel contains 3,000 devices.
(2) Lead-free packaging only. Device is WEEE and RoHS compliant
and halogen-free.
MLPD; 3 x 3, 10 LEAD
θ
JA
=
40°C/W
Marking Information
410A
yyww
xxxx
yyww = Date code
xxxx = Lot number
2
SC410A
Absolute Maximum Ratings
LX to GND (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +28
VIN to PGND, EN to AGND (V) . . . . . . . . . . . . . . . . . -0.3 to +28
VIN to LDO (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 0 . 3
BST to LX (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.0
BST to PGND (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +34
LDO to AGND (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.0
FB, PGOOD, TON (V) . . . . . . . . . . . . . . . . . . . . -0.3 to LDO +0.3
AGND to PGND (V) . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +0.3
Maximum Peak Inductor Current (A) . . . . . . . . . . . . . . . . . 5 . 5
Peak IR Reflow Temperature (°C ) . . . . . . . . . . . . . . . . . . . . . 260
ESD Protection Level (kV)
(1)
. . . . . . . . . . . . . . . . . . . . . . . . . . 2 . 5
Exceeding the above specifications may result in permanent damage to the device or device malfunction. Operation outside of the parameters
specified in the Electrical Characteristics section is not recommended.
NOTES:
(1) Tested according to JEDEC standard JESD22-A114-B.
(2) Calculated from package in still air, mounted to 3 x 4.5 (in), 4 layer FR4 PCB with thermal vias under the exposed pad per JESD51 standards.
Recommended Operating Conditions
Supply Input Voltage (V) . . . . . . . . . . . . . . . . . . . . . . . 7 to 24
Maximum Continuous Output Current (A) . . . . . . . . . . . . . 2
Maximum Peak Inductor Current (A) . . . . . . . . . . . . . . . . . 5.0
Thermal Information
Storage Temperature (°C ) . . . . . . . . . . . . . . . . . . -60 to +150
Maximum Junction Temperature (°C ) . . . . . . . . . . . . . . . . 150
Operating Junction Temperature (°C ) . . . . . . . -40 to +125
Thermal Resistance, Junction to Ambient
(2)
(°C/W ) . . . . 40
Electrical Characteristics
Unless specified: V
IN
=12V, T
A
=+25°C for Typ, -40°C to +85°C for Min and Max, T
J
< 125°C, per detailed application circuit
Parameter
Input Supplies
Conditions
Min
Typ
Max
Units
Internal Bias UVLO Threshold
Internal Bias UVLO Hysteresis
Rising UVLO V
TH
4
0.3
V
V
μA
mA
VIN Supply Current
V
EN
= 0V
I
OUT
= 0A
(1)
225
0.8
Controller
FB On-Time Threshold
Frequency Programming Range
FB Input Bias Current
See R
TON
Calculation
FB=5V or 0V
0.7425
200
-1
0.75
0.7575
1000
+1
V
kHz
μA
Timing
On-Time
Minimum On-Time
(1)
Minimum Off-Time
(1)
Auto-recovery Interval
Continuous Mode V
IN
=15V, V
OUT
=3V, R
TON
= 200kΩ
0.9
1
100
320
28
1.1
μs
ns
ns
ms
3
SC410A
Electrical Characteristics (continued)
Parameter
Soft start
Soft start Time
(1)
Delay from PWM Switching to Output Regulation
850
µs
Conditions
Min
Typ
Max
Units
Current Sense
Zero-Crossing Detector Threshold
LX - PGND
-10
0
+10
mV
Power Good
Power Good Threshold
Upper Limit, V
FB
> internal 750mV reference
Lower Limit, V
FB
< internal 750mV reference
PGOOD Delay Time
(1)
Noise Immunity Delay Time
(1)
Leakage
Power Good On-Resistance
10
Between VOUT at 90% of its regulation value
and the PGOOD signal transitioning to high
120
90
1
5
1
%V
REF
ms
µs
µA
Ω
Fault Protection
Output Under-Voltage Fault
Output Over-Voltage Fault
Smart PowerSave Protection Threshold
OV, UV Fault Noise Immunity Delay
(1)
Over-Temperature Shutdown
(1)
Over-Temperature Shutdown Hysterisis
(1)
FB with Respect to REF,
8 Consecutive Switching Cycles
FB with Respect to REF
FB with Respect to REF
75
120
110
5
145
10
%V
REF
%V
REF
%V
REF
μs
°C
°C
Enable Logic
PWM Output Enabled
(1)
EN Input Bias Current
V
EN
= 5V
-10
0.8
10
V
μA
Gate Drivers
BST Switch On resistance
25
Ω
4
SC410A
Electrical Characteristics (continued)
Parameter
Internal Power MOSFETs
Current Limit
LX Leakage Current
Inductor Valley Current Limit, VLDO=5V
VIN=24V, LX=0V, High Side
High Side
Switch Resistance
Low Side
Non-overlap time
(1)
110
15
ns
1.5
2
1
215
mΩ
Conditions
Min
Typ
Max
Units
A
10
µA
Linear Regulator
(The LDO is shorted to the bias node, internally)
LDO Accuracy
Short circuit protection, V
IN
= 12V, V
LDO
<80% of
final V
LDO
value
Operating current limit, V
IN
= 12V, V
LDO
> 80% of
final V
LDO
value
From V
IN
to V
LDO
, I
LDO
= 100mA
-4
35
mA
100
0.75
V
4
%V
LDO
LDO Current Limit
LDO Drop Out Voltage
Note:
(1) Typical value from EVB, not ATE tested.
5
京公网安备 11010802033920号
EEWORLD
