MIC4685 Datasheet, PDF (3/15 Pages) Micrel Semiconductor – 3A SPAK SuperSwitcher™ Buck Regulator

MIC4685
Absolute Maximum Ratings (Note 1)
Supply Voltage (V_IN), Note 1 ...................................... +34V
Enable Voltage (V_EN) .................................... –0.3V to +V_IN
Steady-State Output Switch Voltage (V_SW) ....... –1V to V_IN
Feedback Voltage (V_FB) .............................................. +12V
Storage Temperature (T_S) ....................... –65°C to +150°C
ESD Rating Note 3 ....................................................... 2kV
Micrel
Operating Ratings (Note 2)
Supply Voltage (V_IN) Note 4 ........................... +4V to +30V
Junction Temperature (T_J) ....................... –40°C to +125°C
Package Thermal Resistance
θ_JA, SPAK-7 Lead ............................................ 11.8°C/W
θ_JC, SPAK-7 Lead .............................................. 2.2°C/W
Electrical Characteristics
V_IN = V_EN = 12V, V_OUT = 5V; I_OUT = 500mA; T_A = 25°C, unless otherwise noted. Bold values indicate –40°C ≤ T_J ≤ +125°C.
Parameter
Condition
Min Typ Max
Units
Feedback Voltage
(±2%)
(±3%)
1.210 1.235 1.260 V
1.198
1.272 V
8V ≤ V_IN ≤ 30V, 0.1A ≤ I_LOAD ≤ 1A, V_OUT = 5V, Note 4
1.186 1.235 1.284 V
1.173
1.297 V
Feedback Bias Current
50
nA
Maximum Duty Cycle
Output Leakage Current
Quiescent Current
Bootstrap Drive Current
Bootstrap Voltage
Frequency Fold Back
Oscillator Frequency
V_FB = 1.0V
V_IN = 30V, V_EN = 0V, V_SW = 0V
V_IN = 30V, V_EN = 0V, V_SW = –1V
V_FB = 1.5V
V_FB = 1.5V, V_SW = 0V
I_BS = 10mA, V_FB = 1.5V, V_SW = 0V
V_FB = 0V
94
%
5
500
µA
1.4
20
mA
6
12
mA
250 380
mA
5.5
6.2
V
30
70
120 kHz
180 200 225 kHz
Saturation Voltage
Short Circuit Current Limit
Shutdown Current
Enable Input Logic Level
I_OUT = 1A
V_FB = 0V, See Test Circuit
V_EN = 0V
regulator on
0.59
V
3.5
6
A
150 200
µA
2
V
regulator off
0.8
V
Enable Pin Input Current
Thermal Shutdown @ T_J
V_EN = 0V (regulator off)
V_EN = 12V (regulator on)
16
50
µA
–1 –0.83
mA
160
°C
Note 1.
Note 2.
Note 3.
Note 4.
Exceeding the absolute maximum rating may damage the device.
The device is not guaranteed to function outside its operating rating.
Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5kΩ in series with 100pF.
2.5V of headroom is required between V_IN and V_OUT. The headroom can be reduced by implementing a bootstrap diode as seen on the 5V to
3.3V circuit on page 1.
September 2002
3
MIC4685