Texas Instruments TPS7H4010EVM, User Manual

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compromise operation of the source. The input filter helps to smooth out the voltage
perturbations leading to the source.
EN_A (TP12)
EN_B (TP26) Test point to monitor the EN pin of the device
EN_A Jumper
(J6) EN_B
Jumper (J15) Set EN pin options
As noted on the board, this jumper selects which voltage is used to enable the device
(schematic is shown in
Figure 1-3 )
1. PIN-1 to PIN-2: EN_x is connected to EN_EXT_x test point through a resistor divider.
2. PIN-2 to PIN-3 (default): EN_x is connected to PVIN_x through a resistor divider.
The default setting is jumper on PIN-2 and PIN-3. The board will start when PVIN is about
3.5 V with this setting. The EN voltage is calculated by
Equation 1 .
V
EN
= PVIN × R
ENB
/ (R
ENT
+ R
ENB
) (1)
When PIN-1 and PIN-2 are connected, the EN voltage is calculated by Equation 2 .
V
EN
= V
EN_EXT
× R
ENB
/ (R
ENT
+ R
ENB
) (2)
If a resistor divider is not desired, the R
ENB
can be removed from the board and the EN pin
voltage will be equal to either EN_EXT_x or PVIN voltage, depending on the jumper
location. It is recommended to keep R
ENT
as a current limiting and noise filtering resistor at
EN pin.
EN_EXT_A (TP14)
EN_EXT_B (TP28) External voltage input to drive EN
When EN_x jumper has PIN-1 and PIN-2 connected, the enable threshold is driven by the
voltage on the EN_EXT_x test point. The EN_x pin voltage can be found by
Equation 2 .
Remove R
ENB
from the board if it is desired to have the same voltage on the EN pin as the
EN_EXT_x voltage (schematic is shown in Figure 1-3 ).
PGOOD_A (TP11)
PGOOD_B (TP25) Test point to monitor the PGOOD_x pin
PGOOD_x test points are used to monitor the power-good flag. This flag indicates whether
the output voltage has reached its regulation level. The PGOOD pin of the device is an
open-drain output that is pulled up to V
OUT
on this board through 100kohm resistor.
MODE_A Jumper
(J7) MODE_B
Jumper (J16) Operation mode setting and synchronization clock input
As noted on the PCB, the MODE_x jumper is used to select the desired light-load operation
mode.
1. PIN-1 to PIN-2: FPWM mode;
2. PIN-2 to PIN-3 (default): auto mode;
3. Open, connect external clock input to SYNC_x test points (TP13, TP27) for
synchronization and FPWM mode.
The default is PIN-2 and PIN-3 connected together and the device will operate in auto
mode at light loads. With auto mode, discontinuous conduction mode (DCM) and pulse
frequency modulation (PFM) mode are employed at light loads to provide high efficiency.
PFM mode also provides very low quiescent current at no load. At heavier load, when
inductor current is in DCM or continuous conduction mode (CCM) operation, the switching
frequency is determined by the RT resistors (R6, R16) on the board, which is either 500
kHz.
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8 TPS7H4010EVM User's Guide SNVU744 – OCTOBER 2020
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