Low-Noise, 14V Input, 1A, PWM
Step-Down Converters
MAX1684/MAX1685
ABSOLUTE MAXIMUM RATINGS
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 ..........................................................10mA to -1mA
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, 10sec ) ............................+300°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.
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 other-
wise noted. Typical values are at T
A
= +25°C.)
PARAMETER
Input Voltage Range
Feedback Voltage
Output Voltage (3.3V mode)
Output Load Regulation
Output Current Capability
Output Adjust Range
FB Input Current
On-Resistance, P-Channel
On-Resistance, N-Channel
Current Limit in PWM Mode
Pulse-Skipping Current Threshold
Current Limit in Low-Power
Mode
Current Limit, N-Channel
Zero Crossing Threshold
I
LIMLP
I
LIM
SYNC/PWM = low
STBY
= low
SYNC/PWM = high
SYNC/PWM = low
PWM mode,
SYNC/PWM = high,
V
BOOT
= 3.3V
(Note 2)
Quiescent Power Consumption
MAX1684
MAX1685
MAX1684
MAX1685
I
FB
V
FB
V
OUT
V
FB
= V
OUT
, I
LOAD
= 0 to 1A
FB = AGND, I
LOAD
= = 0 to 1A
V
FB
= V
OUT
, I
LOAD
= 0 to 1A
V
IN
= 5V to 14V
BOOT = AGND (Note 1)
V
FB
= 1.4V
High-side switch,
I
LX
= 1A
V
IN
= 6V
V
IN
= 2.7V
1.2
285
285
0.15
20
40
1
V
REF
-50
0.24
0.34
3
1.75
380
380
0.4
50
80
13
25
0.9
0.14
V
IN
50
0.5
0.8
8
2.3
475
475
0.9
80
120
33
65
mW
2
0.27
SYMBOL
CONDITIONS
MIN
2.7
1.238
3.3
1.251
3.333
0.01
TYP
MAX
14
1.264
3.365
UNITS
V
V
V
%
A
V
nA
Ω
Ω
A
mA
mA
A
mA
Low-side switch, V
IN
= 2.7V, I
LX
= 200mA
Normal mode, SYNC/PWM = low,
V
BOOT
= 3.3V (Note 2)
Low-power mode,
STBY
= low,
V
BOOT
= 3.3V (Note 2)
2
_______________________________________________________________________________________
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
