Data Sheet
12V Pico TLynxTM 6A: Non-isolated DC-DC Power Modules
4.5 – 14Vdc input; 0.59Vdc to 5.5Vdc output; 6A output current
September 4, 2009
16
14
12
VIN+
MODULE
Upper Limit
Rpullup
1.5MEG
10
8
6
I
ON/OFF
PWM Enable
Q1
4
2
0
ON/OFF
+
Lower Limit
22K
22K
V
ON/OFF
Q2
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
5.5
6
Output Voltage (V)
GND
_
Figure 44. Output Voltage vs. Input Voltage Set
Point Area plot showing limits where the output
voltage can be set for different input voltages.
Figure 43. Circuit configuration for using negative
On/Off logic.
Without an external resistor between Trim and GND
pins, the output of the module will be 0.59Vdc. To
calculate the value of the trim resistor, Rtrim for a
desired output voltage, use the following equation:
Overcurrent Protection
To provide protection in a fault (output overload)
condition, the unit is equipped with internal
current-limiting circuitry and can endure current limiting
continuously. At the point of current-limit inception, the
unit enters hiccup mode. The unit operates normally
once the output current is brought back into its
specified range.
⎡
⎤
5.91
Vo − 0.591
Rtrim =
kΩ
⎢
⎥
⎦
(
)
⎣
Rtrim is the external resistor in kΩ
Vo is the desired output voltage.
Overtemperature Protection
Table 1 provides Rtrim values required for some
common output voltages.
To provide protection in a fault condition, the unit is
equipped with a thermal shutdown circuit. The unit will
shutdown if the overtemperature threshold of 140oC is
exceeded at the thermal reference point Tref . The
thermal shutdown is not intended as a guarantee that
the unit will survive temperatures beyond its rating.
Once the unit goes into thermal shutdown it will then
wait to cool before attempting to restart.
Table 1
VO, set (V)
0.6
Rtrim (KΩ)
656.7
1.0
14.45
1.2
9.704
1.5
1.8
6.502
4.888
Input Undervoltage Lockout
2.5
3.3
5.0
3.096
2.182
1.340
At input voltages below the input undervoltage lockout
limit, the module operation is disabled. The module
will begin to operate at an input voltage above the
undervoltage lockout turn-on threshold.
By using a ±0.5% tolerance trim resistor with a TC of
±100ppm, a set point tolerance of ±1.5% can be
achieved as specified in the electrical specification.
Output Voltage Programming
The output voltage of the 12V Pico TLynxTM 6A
modules can be programmed to any voltage from
0.59dc to 5.5Vdc by connecting a resistor between the
Trim and GND pins of the module. Certain restrictions
apply on the output voltage set point depending on the
input voltage. These are shown in the Output Voltage
vs. Input Voltage Set Point Area plot in Fig. 44. The
Upper Limit curve shows that for output voltages of
0.9V and lower, the input voltage must be lower than
the maximum of 14V. The Lower Limit curve shows
that for output voltages of 3.8V and higher, the input
voltage needs to be larger than the minimum of 4.5V.
Remote Sense
The 12V Pico TLynxTM 6A power modules have a
Remote Sense feature to minimize the effects of
distribution losses by regulating the voltage at the
SENSE pin. The voltage between the SENSE pin and
VOUT pin must not exceed 0.5V. Note that the output
voltage of the module cannot exceed the specified
maximum value. This includes the voltage drop
between the SENSE and Vout pins. When the
LINEAGE POWER
14