MIC4684_10 Datasheet, PDF (3/16 Pages) Micrel Semiconductor – 2A High-Efficiency SuperSwitcher Buck Regulator

MIC4684
Absolute Maximum Ratings (Note 1)
Supply Voltage (V_IN), Note 3....................................... +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
Micrel, Inc.
Operating Ratings (Note 2)
Supply Voltage (V_IN) Note 4............................ +4V to +30V
Ambient Temperature (T_A)........................... –40°C to +85°C
Junction Temperature (T_J)......................... –40°C to +125°C
Package Thermal Resistance
θ_JA, Note 5........................................................... 75°C/W
θ_JC, Note 5........................................................... 25°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

1.186 1.235 1.284 V
1.173 1.297 V
Feedback Bias Current
50
nA
Maximum Duty Cycle
V_FB = 1.0V
94
%
Output Leakage Current
V_IN = 30V, V_EN = 0V, V_SW = 0V
5
500
µA
V_IN = 30V, V_EN = 0V, V_SW = –1V
1.4
20
mA
Quiescent Current
V_FB = 1.5V
6
12
mA
Bootstrap Drive Current
V_FB = 1.5V, V_SW = 0V
250 380
mA
Bootstrap Voltage
I_BS = 10mA, V_FB = 1.5V, V_SW = 0V
5.5
6.2
V
Frequency Fold Back
V_FB = 0V
30
50
120 kHz
Oscillator Frequency
180 200 225 kHz
Saturation Voltage
Short Circuit Current Limit
Shutdown Current
Enable Input Logic Level
I_OUT = 1A
0.59
V
V_FB = 0V, See Test Circuit
2.2
A
V_EN = 0V
150
µA
regulator on
2
V
regulator off
0.8
V
Enable Pin Input Current
V_EN = 0V (regulator off)
16
50
µA
V_EN = 12V (regulator on)
–1 –0.83
mA
Thermal Shutdown @ T_J
160
°C
Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3. Devices are ESD sensitive. Handling precautions recommended.
Note 4. 2.5V of headroom is required between V_IN and V_OUT. The headroom can be reduced by implementing a feed-forward diode a seen on the 5V
to 3.3V circuit on page 1.
Note 5. Measured on 1” square of 1 oz. copper FR4 printed circuit board connected to the device ground leads.
January 2010
3
M9999-012610