SLVSAA4B – JUNE 2010 – REVISED JANUARY 2011
www.ti.com
PACKAGE DISSIPATION RATINGS
(1)
PACKAGE
RHA
(1)
q
JA
(°C/W)
30
T
A
= 25°C
POWER RATING (W)
3.33
T
A
= 55°C
POWER RATING (W)
2.3
T
A
= 85°C
POWER RATING (W)
1.3
Based on JEDEC 51.5 HIGH K environment measured on a 76.2 x 114 x .6-mm board with the following layer arrangement:
(a) Top layer: 2 Oz Cu, 6.7% coverage
(b) Layer 2: 1 Oz Cu, 90% coverage
(c) Layer 3: 1 Oz Cu, 90% coverage
(d) Bottom layer: 2 Oz Cu, 20% coverage
ELECTRICAL CHARACTERISTICS
T
J
= -40°C to 125°C, VIN = 12 V, f
SW
= 1 MHz (unless otherwise noted)
PARAMETER
INPUT SUPPLY UVLO AND INTERNAL SUPPLY VOLTAGE
V
IN
IDD
SDN
IDD
Q
Input Voltage range
Shutdown
Quiescent, low power disabled (Lo)
EN pin = low for all converters
Converters enabled, no load
Buck 1 = 3.3 V, Buck 2 = 2.5 V,
Buck 3 = 7.5 V
Converters enabled, no load
Buck 1 = 3.3 V, Buck 2 = 2.5 V,
Buck 3 = 7.5 V
Rising V
IN
Falling V
IN
Both edges
Internal biasing supply
Internal biasing supply
UVLO for internal V7V rail
Rising V7V
Falling V7V
Falling edge
4.5
1.3
20
18
V
mA
mA
TEST CONDITIONS
MIN
TYP
MAX
UNIT
IDD
Q_LOW_P
Quiescent, low power enabled (Hi)
1.5
4.22
4.1
110
3.3
6.25
3.8
3.6
110
mA
UVLO
VIN
UVLO
DEGLITCH
V3V
V7V
V7V
UVLO
V7V
UVLO_DEGLITCH
V
IN
under voltage lockout
V
µs
V
V
V
µs
BUCK CONVERTERS (ENABLE CIRCUIT, CURRENT LIMIT, SOFT START, SWITCHING FREQUENCY AND SYNC CIRCUIT, LOW
POWER MODE)
VIH
VIL
ICH
EN
t
D
I
SS
F
SW_BK
R
FSW
f
SW_TOL
V
SYNCH
V
SYNCL
SYNC
RANGE
SYNC
CLK_MIN
SYNC
CLK_MAX
VIH
LOW_P
VIL
LOW_P
Enable threshold high
Enable treshold Low
Pull up current enable pin
Discharge time enable pins
Soft start pin current source
Converter switching frequency range
Frequency setting resistor
Internal oscillator accuracy
External clock threshold high
External clock treshold Low
Synchronization range
Sync signal minimum duty cycle
Sync signal maximum duty cycle
Low power mode threshold high
Low power mode treshold Low
V3p3 = 3.3 V
V3p3 = 3.3 V
V
IN
= 12V T
J
= 25°C
V
IN
= 4.5 to 18V
-1%
-2%
0.8
0.8
80
1.55
1.24
1%
2%
120
Set externally with resistor
Depending on set frequency
f
SW
= 800 kHz
V3p3 = 3.3 V
V3p3 = 3.3 V
0.2
40
60
0.3
50
-10
1.55
1.24
2.2
Power-up
V3p3 = 3.2 V - 3.4 V
V3p3 = 3.2 V - 3.4 V
1.1
10
5
2.2
600
10
1.55
1.24
V
V
µA
ms
µA
MHz
kΩ
%
V
V
MHz
%
%
V
V
FEEDBACK, REGULATION, OUTPUT STAGE
V
FB
t
ON_MIN
Feedback voltage
Minimum on time
(current sense blanking)
V
ns
6
Product Folder Link(s):
Copyright © 2010–2011, Texas Instruments Incorporated
TI [ TEXAS INSTRUMENTS ]
