7.8 Electrical Characteristics: All Output Voltage Versions (5)
Specifications with standard type face are for TJ = 25°C, and those in bold type face apply over full Operating Temperature Range. Unless otherwise specified, VIN = 5V.
PARAMETER |
TEST CONDITIONS |
TYP |
MIN |
MAX |
UNIT |
IS |
Input Supply Current |
Switch Off(8) |
11 |
|
15.5/16.5 |
mA |
ISWITCH = 3.0A |
85 |
|
140/165 |
mA |
IS/D |
Shutdown Input
Supply Current |
VSH = 3V |
16 |
|
100/300 |
μA |
VUV |
Input Supply
Undervoltage Lockout |
RLOAD = 100Ω |
3.30 |
3.05 |
3.75 |
V |
fO |
Oscillator Frequency |
Measured at Switch Pin
RLOAD = 100Ω, VCOMP = 1.0V
Freq. Adj. Pin Open (Pin 1) |
100 |
85/75 |
115/125 |
kHz |
RSET = 22 kΩ |
200 |
|
|
kHz |
fSC |
Short-Circuit Frequency |
Measured at Switch Pin
RLOAD = 100Ω
VFEEDBACK = 1.15V |
|
|
|
|
25 |
|
|
kHz |
|
|
|
|
VEAO |
Error Amplifier Output Swing |
Upper Limit(7) |
2.8 |
2.6/2.4 |
|
V |
Lower Limit(8) |
0.25 |
|
0.40/0.55 |
V |
IEAO |
Error Amp Output Current (Source or Sink) |
See(9) |
165 |
110/70 |
260/320 |
μA |
ISS |
Soft Start Current |
VFEEDBACK = 0.92V
VCOMP = 1.0V |
11.0 |
8.0/7.0 |
17.0/19.0 |
μA |
DMAX |
Maximum Duty Cycle |
RLOAD = 100Ω(7) |
98 |
93/90 |
|
% |
IL |
Switch Leakage Current |
Switch Off
VSWITCH = 60V |
15 |
|
300/600 |
μA |
VSUS |
Switch Sustaining Voltage |
dV/dT = 1.5V/ns |
|
65 |
|
V |
VSAT |
Switch Saturation Voltage |
ISWITCH = 5.0A |
0.7 |
|
1.1/1.4 |
V |
ICL |
NPN Switch Current Limit |
|
6.5 |
5.0 |
9.5 |
A |
VSTH |
Synchronization Threshold Voltage |
FSYNC = 200 kHz
VCOMP = 1V, VIN = 5V |
0.75 |
0.625/0.40 |
0.875/1.00 |
V |
ISYNC |
Synchronization
Pin Current |
VIN = 5V
VCOMP = 1V, VSYNC = VSTH |
100 |
|
200 |
μA |
VSHTH |
ON /OFF Pin (Pin 1) Threshold Voltage |
VCOMP = 1V(10) |
1.6 |
1.0/0.8 |
2.2/2.4 |
V |
ISH |
ON /OFF Pin (Pin 1) Current |
VCOMP = 1V
VSH = VSHTH |
40 |
15/10 |
65/75 |
μA |
θJA
θJA
θJC |
Thermal Resistance |
NDZ Package, Junction to Ambient(11)
NDZ Package, Junction to Ambient(12)
NDZ Package, Junction to Case |
65
45
2 |
|
|
°C/W |
θJA
θJA
θJA
θJC |
KTW Package, Junction to Ambient(13)
KTW Package, Junction to Ambient(14)
KTW Package, Junction to Ambient(15)
KTW Package, Junction to Case |
56
35
26
2 |
|
|
(1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. These ratings apply when the current is limited to less than 1.2 mA for pins 1, 2, 3, and 6. Operating ratings indicate conditions for which the device is intended to be functional, but device parameter specifications may not be ensured under these conditions. For ensured specifications and test conditions, see the Electrical Characteristics.
(2) Note that switch current and output current are not identical in a step-up regulator. Output current cannot be internally limited when the LM2588 is used as a step-up regulator. To prevent damage to the switch, the output current must be externally limited to 5A. However, output current is internally limited when the LM2588 is used as a flyback regulator (see the section for more information).
(3) The junction temperature of the device (TJ) is a function of the ambient temperature (TA), the junction-to-ambient thermal resistance (θJA), and the power dissipation of the device (PD). A thermal shutdown will occur if the temperature exceeds the maximum junction temperature of the device: PD × θJA + TA(MAX) ≥ TJ(MAX). For a safe thermal design, check that the maximum power dissipated by the device is less than: PD ≤ [TJ(MAX) − TA(MAX)]/θJA. When calculating the maximum allowable power dissipation, derate the maximum junction temperature—this ensures a margin of safety in the thermal design.
(4) External components such as the diode, inductor, input and output capacitors can affect switching regulator performance. When the LM2588 is used as shown in
Figure 54 and
Figure 55, system performance will be as specified by the system parameters.
(5) All room temperature limits are 100% production tested, and all limits at temperature extremes are specified via correlation using standard Statistical Quality Control (SQC) methods.
(6) A 1.0 MΩ resistor is connected to the compensation pin (which is the error amplifier output) to ensure accuracy in measuring AVOL.
(7) To measure this parameter, the feedback voltage is set to a low value, depending on the output version of the device, to force the error amplifier output high and the switch on.
(8) To measure this parameter, the feedback voltage is set to a high value, depending on the output version of the device, to force the error amplifier output low and the switch off.
(10) When testing the minimum value, do not sink current from this pin—isolate it with a diode. If current is drawn from this pin, the frequency adjust circuit will begin operation (see
Figure 20).
(11) Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with ½ inch leads in a socket, or on a PC board with minimum copper area.
(12) Junction to ambient thermal resistance (no external heat sink) for the 7 lead TO-220 package mounted vertically, with ½ inch leads soldered to a PC board containing approximately 4 square inches of (1 oz.) copper area surrounding the leads.
(13) Junction to ambient thermal resistance for the 7 lead TO-263 mounted horizontally against a PC board area of 0.136 square inches (the same size as the TO-263 package) of 1 oz. (0.0014 in. thick) copper.
(14) Junction to ambient thermal resistance01242001 for the 7 lead TO-263 mounted horizontally against a PC board area of 0.4896 square inches (3.6 times the area of the TO-263 package) of 1 oz. (0.0014 in. thick) copper.
(15) Junction to ambient thermal resistance for the 7 lead TO-263 mounted horizontally against a PC board copper area of 1.0064 square inches (7.4 times the area of the TO-263 package) of 1 oz. (0.0014 in. thick) copper. Additional copper area will reduce thermal resistance further. See the thermal model in Switchers Made Simple® software.