PTN78000A
www.ti.com
SLTS246A – APRIL 2005 – REVISED MAY 2005
ELECTRICAL CHARACTERISTICS
operating at 25°C free-air temperature, V
I
= 12 V, V
O
= –5 V, I
O
= I
O
(max), C
1
= 100 µF, C
2
= 2x 4.7 µF, C
3
= 100 µF (unless
otherwise noted)
PARAMETER
TEST CONDITIONS
V
O
= –15 V
I
O
Output current
T
A
= 85°C, natural convection airflow
V
O
= –12 V
V
O
= –5 V
V
O
= –3.3 V
V
O
= –15 V
V
I
Input voltage range
Over I
O
range
V
O
= –12 V
V
O
= –5 V
V
O
= –3.3 V
Set-point voltage tolerance
Temperature variation
V
O
Line regulation
Load regulation
Total output voltage vari-
ation
V
O
Adj
Output voltage adjust
range
T
A
= 25°C
–40°C to +85°C
Over V
I
range
Over I
O
range
Includes set point, line, load
–40 < T
A
< 85°C
7 V
≤
V
I
≤
(32 – |V
O
|) V
V
I
= 12 V, R
SET
= 100
Ω,
V
O
= –15 V
η
Efficiency
V
I
= 12 V, R
SET
= 2 kΩ, V
O
= –12 V
V
I
= 12 V, R
SET
= 28.7 kΩ, V
O
= –5 V
V
I
= 12 V, R
SET
= 221 kΩ, V
O
= –3.3 V
Output voltage ripple
I
O (LIM)
Current limit threshold
20-MHz bandwidth
∆V
O
= –50 mV
1 A/µs load step from 50% to 100% I
O
max
Transient response
Recovery time
V
O
over/undershoot
F
S
UVLO
C
I
Switching frequency
Undervoltage lockout
External input capacitance
Over V
I
and I
O
ranges
V
I
increasing
Ceramic
Nonceramic
Ceramic
C
O
External output capaci-
tance
Nonceramic
Equivalent series resistance (nonceramic)
MTBF
Calculated reliability
Per Telcordia SR-332, 50% stress,
T
A
= 40°C, ground benign
100
14
(5)
(6)
MIN
0.1
0.1
0.1
0.1
7
7
7
7
TYP
MAX
0.6
0.75
1.5
1.5
17
20
27
28.7
±2%
(1)
(1)
(1)
(1)
(2)
(2)
(2)
(2)
(3)
UNIT
A
V
±0.5%
±10
±10
±3%
–15
83%
84%
82%
77%
1% V
O
3.2
V
(PP)
A
(3)
mV
mV
–3
V
200
1
440
(4)
(4)
µs
%V
O
660
kHz
V
µF
µF
200
1,000
µF
µF
mΩ
10
6
Hrs
550
5.5
9.4
100
8.9
(1)
(2)
(3)
(4)
(5)
(6)
The maximum output current is 1.5 A or the maximum output power is 9 W, whichever is less.
The maximum input voltage is limited and defined to be (32 – |V
O
|) volts.
The set-point voltage tolerance is affected by the tolerance and stability of R
SET
. The stated limit is unconditionally met if R
SET
has a
tolerance of 1% with 100 ppm/°C or better temperature stability.
A 100-µF electrolytic capacitor and two 4.7-µF ceramic capacitors are required across the input (V
I
and GND) for proper operation.
Locate the ceramic capacitance close to the module.
100 µF of output capacitance is required for proper operation. See the application information for further guidance.
This is the typical ESR for all the electrolytic (nonceramic) capacitance. Use 17 mΩ as the minimum when using maximum ESR values
to calculate.
3
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