Rainbow Electronics MAX1685 User Manual
Page 2
MAX1684/MAX1685
Low-Noise, 14V Input, 1A, PWM
Step-Down Converters
2
_______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V
IN
= V
SHDN
= 6V, STBY = SYNC/PWM = CVL, V
BOOT
= V
OUT
, FB = AGND, circuit of Figure 1, T
A
= 0°C to +85°C, unless otherwise
noted. Typical values are at T
A
= +25°C.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
AIN to AGND ............................................................-0.3 to +15V
IN to PGND ................................................-0.3V to (V
AIN
+ 0.3V)
LX to PGND .................................................-0.5V to (V
IN
+ 0.3V)
PGND to AGND ..................................................................±0.3V
SHDN to AGND .........................................-0.3V to (V
AIN
+ 0.3V)
ILIM/SS, FB, CC, BOOT, REF to AGND ....-0.3V to (V
CVL
+ 0.3V)
CVH to IN..................................................................-6V to +0.3V
CVL, STBY, SYNC/PWM to AGND............................-0.3V to +6V
Reference Current ..............................................................±1mA
CVL Current .......................................................-1mA to +10mA
LX Peak Current (Internally Limited) .....................................2.3A
Continuous Power Dissipation (T
A
= +70°C)
16-Pin QSOP (derate 8.3mW/°C above +70°C)............667mW
Operating Temperature Range ...........................-40°C to +85°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
V
FB
= V
OUT
, I
LOAD
= 0 to 1A
Low-power mode, STBY = low,
V
BOOT
= 3.3V (Note 2)
Normal mode, SYNC/PWM = low,
V
BOOT
= 3.3V (Note 2)
PWM mode,
SYNC/PWM = high,
V
BOOT
= 3.3V
(Note 2)
SYNC/PWM = high
Low-side switch, V
IN
= 2.7V, I
LX
= 200mA
High-side switch,
I
LX
= 1A
V
FB
= V
OUT
, I
LOAD
= 0 to 1A
V
IN
= 5V to 14V
BOOT = AGND (Note 1)
SYNC/PWM = low
V
FB
= 1.4V
CONDITIONS
0.14
0.27
Quiescent Power Consumption
0.9
2
25
65
mW
13
33
mA
20
80
130
Zero Crossing Threshold
-10
50
100
V
V
FB
Feedback Voltage
1.238
1.251
1.264
V
2.7
14
Input Voltage Range
A
0.15
0.4
0.9
Current Limit, N-Channel
A
1.2
1.75
2.3
I
LIM
Current Limit in PWM Mode
Ω
3
8
On-Resistance, N-Channel
0.24
0.5
%
0.01
Output Load Regulation
A
1
Output Current Capability
V
V
REF
V
IN
Output Adjust Range
nA
-50
50
I
FB
FB Input Current
UNITS
MIN
TYP
MAX
SYMBOL
PARAMETER
FB = AGND, I
LOAD
= 0 to 1A
V
V
OUT
Output Voltage (3.3V Mode)
3.296
3.333
3.368
V
IN
= 6V
V
IN
= 2.7V
Ω
0.34
0.8
On-Resistance, P-Channel
MAX1684
MAX1685
MAX1684
MAX1685
SYNC/PWM = low
mA
285
380
475
Pulse-Skipping Current Threshold
STBY = low
mA
285
380
475
I
LIMLP
Current Limit in Low-Power
Mode