The following conditions apply, unless otherwise specified.
DC:
Symbol
V
Ref
V
I
= −10V, V
O
= −3V, I
O
= 1A, C
O
= 47µF, R
L
= 2.7KΩ
Parameter
Reference Voltage
Conditions
5mA
≤
I
O
≤
1A
5mA
≤
I
O
≤
1A,
V
O
- 1V
≥
V
I
≥
-26V
V
O
Output Voltage Range
V
I
= -26V
V
RLine
V
RLoad
V
DO
Line Regulation
Load Regulation
Dropout Voltage
I
O
= 5mA, V
O
- 1V
≥
V
I
≥
-26V
50mA
≤
I
O
≤
1A
I
O
= 0.1A,
∆V
O
≤
100mV
I
O
= 1A,
∆V
O
≤
100mV
I
Q
V
ON
Quiescent Current
Dropout Quiescent Current
Output Noise
ON/OFF Input Voltage
ON/OFF Input Current
I
O
≤
1A
V
I
= V
O
, I
O
≤
1A
10Hz - 100KHz, I
O
= 5mA
V
O
: ON
V
O
: OFF
VON/OFF = 0.8V (V
O
: ON)
VON/OFF = 2.4V (V
O
: OFF)
I
L
I
Limit
Output Leakage Current
Current Limit
V
I
= -26V, VON/OFF = 2.4V,
V
O
= 0V
V
O
= 0V
1.5
1.0
2.4
10
25
100
150
250
300
2.5
4.0
-24
-25
-26
-12
-15
+26
+12
+15
0.2
0.3
0.8
1.0
5.0
50
450
500
0.8
Notes
Min
Max
Units
V
V
V
V
V
mV
mV
mV
V
V
V
V
mA
mA
µV
µV
V
V
µA
µA
µA
µA
µA
µA
A
A
Sub-
groups
1
2, 3
1
1
2, 3
1, 2, 3
1
2, 3
1
2, 3
1
2, 3
1, 2, 3
1, 2, 3
1
2, 3
1, 2, 3
1, 2, 3
1
2, 3
1
2, 3
1
2, 3
1
2, 3
-1.234 -1.186
-1.27 -1.15
-3.0
AC Parameters
The following conditions apply, unless otherwise specified.
AC:
Symbol
RR
V
I
= −10V, V
O
= −3V, I
O
= 1A, C
O
= 47µF, R
L
= 2.7KΩ
Parameter
Ripple Rejection
Conditions
V
Ripple
= 1V
RMS
, F
Ripple
= 1KHz,
I
O
= 5mA
Notes
Min
50
Max
Units
dB
Sub-
groups
1
www.national.com
4
LM2991QML
LM2991 Electrical Characteristics
DC Drift Parameters
(Continued)
The following conditions apply, unless otherwise specified.
DC:
V
I
= −10V, V
O
= −3V, I
O
= 1A, C
O
= 47µF, R
L
= 2.7KΩ Deltas not required on B−Level product. Deltas required for
S−Level product ONLY.
Symbol
V
Ref
Parameter
Reference Voltage
Conditions
5mA
≤
I
O
≤
1A
Notes
Min
Max
Units
mV
Sub-
groups
1
±
20
Note 1:
Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is
functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed
specifications apply only for the test conditions listed. Some performance characteristics may degrade when the device is not operated under the listed test
conditions.
Note 2:
The maximum power dissipation must be derated at elevated temperatures and is dictated by T
Jmax
(maximum junction temperature),
θ
JA
(package junction
to ambient thermal resistance), and T
A
(ambient temperature). The maximum allowable power dissipation at any temperature is P
Dmax
= (T
Jmax
- T
A
)/θ
JA
or the
number given in the Absolute Maximum Ratings, whichever is lower.
Note 3:
The package material for these devices allows much improved heat transfer over our standard ceramic packages. In order to take full advantage of this
improved heat transfer, heat sinking must be provided between the package base (directly beneath the die), and either metal traces on, or thermal vias through, the
printed circuit board. Without this additional heat sinking, device power dissipation must be calculated using
θ
JA
, rather than
θ
JC
, thermal resistance. It must not be
assumed that the device leads will provide substantial heat transfer out the package, since the thermal resistance of the leadframe material is very poor, relative to
the material of the package base. The stated
θ
JC
thermal resistance is for the package material only, and does not account for the additional thermal resistance
between the package base and the printed circuit board. The user must determine the value of the additional thermal resistance and must combine this with the
stated value for the package, to calculate the total allowed power dissipation for the device. The user must determine the value of the additional thermal resistance
and must combine this with the stated value for the package, to calculate the total allowed power dissipation for the device.
