The JTMA7120 ,JTMA7120A is a fixed 300kHz frequency, voltage(3)

the low-side MOSFET) is less than the internal over-current reference voltage (0.4V, typical), the IC shuts
off the converter and then initiates a new soft-start process. After 4 over-current events are counted, the
device turns off both high-side and low-side MOSFETs and the converter’s output is latched to be floating.
Please pay attention to the RC delay effect. It causes the OCP trip level to be the function of the
operating duty. The parasitic capacitance, includ-ing the capacitance inside the OCSET, external PCB
trace capacitance, and the COSS of the shutdown MOSFET, must be minimized, especially selecting a
shutdown MOSFET with very small COSS. The OCP trip level follows the duty to increase a little at low
operating duty, but very much at high operating duty,like the RC delay curve. Due to load regulation or
current-limit, heavy load normally reduces converter’s input voltage and increases the power loses. During
heavy load, the JTMA7120 regulates the output voltage by expending the duty. This rises up the OCP trip level
at the same time.
Under-Voltage Protection (UVP)
The under-voltage function monitors the FB voltage (VFB) to protect the converter against short-circuit
conditions. When the VFB falls below the falling UVP threshold (67% VREF), the JTMA7120 shuts off the
converter. After a preceding delay, which starts at the beginning of the under-voltage shutdown, the
JTMA 7120 initiates a new soft-start to resume regulating. The under-voltage protection shuts off
and then re-starts the converter repeatedly without latching. The function is disabled during soft-start
process.
Over-Voltage Protection (OVP)
The over-voltage protection monitors the FB voltage to prevent the output from over-voltage. When the
output voltage rises to 118% of the nominal output voltage, the JTMA7120 turns on the low-side MOSFET
until the output voltage falls below the OVP threshold, regulating the output voltage around the
OVP thresholds.

Adaptive Shoot-Through Protection
The gate driver incorporates adaptive shoot-through protection to high-side and low-side MOSFETs from
conducting simultaneously and shorting the input supply. This is accomplished by ensuring the falling
gate has turned off one MOSFET before the other is allowed to rise.
During turn-off of the low-side MOSFET, the LGATE voltage is monitored until it reaches a 1.5V threshold,
at which time the UGATE is released to rise after a constant delay. During turn-off of the high-side
MOSFET, the UGATE-to-PHASE voltage is also monitored until it reaches a 1.5V threshold, at which
time the LGATE is released to rise after a constant delay.

Shutdown Control
Pulling the OCSET voltage below 0.15V by an open drain transistor, shown in typical application circuit,
shuts down the JTMA7120 PWM controller. In shut-down mode, the UGATE and LGATE are pulled to
PHASE and GND respectively, the output is floating.

八,相关产品

Part_No	Package & Pins	Topology	Architecture	Phase	No. of PWM Outputs	Output Current (max)(A)	Input Voltage (V)		Reference Voltage(V)	Bias Voltage (typ) (V)	Quiescent Current (typ)(uA)
Part_No	Package & Pins	Topology	Architecture	Phase	No. of PWM Outputs	Output Current (max)(A)	min	max	Reference Voltage(V)	Bias Voltage (typ) (V)	Quiescent Current (typ)(uA)
JTMA7068	SOP-14	Buck	VM	1	1	30	2.9	13.2	0.9	12	8000
	QSOP-16
	QFN4x4-16
JTMA7065	SOP-8	Buck	VM	1	1	20	2.9	13.2	0.8	12	5000
JTMA7065C	SOP-8	Buck	VM	1	1	20	2.9	13.2	0.8	12	5000
JTMA7098	QFN4x4-24	Multiphase	VM	2	1	60	3.1	13.2	0.6	12	5000
JTMA7120	SOP-8	Buck	VM	1	1	20	2.2	13.2	0.8	###	2100
JTMA7120A	SOP-8	Buck	VM	1	1	20	2.2	13.2	0.8	###	2100
JTMA7037/A/B	SOP-8	Buck	VM	1	1	5	5	13.2	1.25 / 0.8	###	3000
JTMA7037/A/B	TSSOP-8	Buck	VM	1	1	5	5	13.2	1.25 / 0.8	###	3000
JTMA7057	SOP-8	Buck	VM	1	1	10	3.3	5.5	0.8	5	2100
JTMA7062B	SOP-14	Buck	VM	1	1	10	5	13.2	0.8	12	2000
JTMA7066	TSSOP-24	Buck	VM	1	2	20	5	13.2	0.6	###	4000
JTMA7066	QFN5x5-32	Buck	VM	1	2	20	5	13.2	0.6	###	4000
JTMA7067N	SOP-14	Buck	VM	1	1	30	2.9	13.2	0.9	12	4000
	QSOP-16
	QFN-16
JTMA7073	SOP-14	Buck	VM	1	1	30	2.2	13.2	0.6	12	5000
JTMA7073A	SOP-14	Buck	VM	1	1	30	2.2	13.2	0.6	12	5000
JTMA7074	SOP-14	Buck	VM	1	1	25	2.2	13.2	0.8	12	5000
JTMA7095/A	LQFP7x7-48	Buck	VM	1	6	0.015	1.4	6.5	-	5	1800
	TQFN7x7-48	Boost
		Flyback
JTMA7116	TSSOP-24P	Buck	VM	1	2	20	2.97	5.5	0.8	###	5000
JTMA7063	SOP-14	Buck	VM	1	1	10	5	13.2	0.8	12	3000
JTMA7064	SOP-8-P	Buck	VM	1	1	30	2.9	13.2	1.2	12	3000
JTMA7064	DIP-8	Buck	VM	1	1	30	2.9	13.2	1.2	12	3000
JTMA7108	SSOP-28	Buck	VM	1	2	20	5	24	0.9	5	1200
JTMA7108	QFN4x4-24	Buck	VM	1	2	20	5	24	0.9	5	1200
JTMA7158	SOP-20	Buck	VM	1	2	20	2.2	13.2	0.6	###	4000
JTMA7181	SOP-8		VM	1	2	-	-	-	-	###	550
JTMA7181	DFN3x3-10		VM	1	2	-	-	-	-	###	550
JTMA38HC/42/3/4/5A	DIP-8	Buck	VM	1	1	1	1.2	9	24	5	9 ~ 24
	SOP-8	Boost
		Flyback
		Forward
JTMA7138	SSOP-16	Buck	VM	1	1	25	3	25	0.6	5	1700
	QFN4x4-16
	TQFN3x3-16
JTMA7199	TDFN3x3-10	Buck	COT	1	1	25	3	25	0.5	5	350
JTMA8700	QFN4x4-24	Buck	CM	2	1	40	4.5	13.2	0.6	###	4000
JTMA8720B	SOP8-P	Buck	VM	1	1	20	3	13.2	0.8	###	2500
JTMA8720B	TDFN3x3-10	Buck	VM	1	1	20	3	13.2	0.8	###	2500
JTMA8722A/B/C/D	SOP8-P	Buck	VM	1	1	25	3	13.2	0.6 /0.8	###	1200
JTMA8723	TDFN3x3-10	Buck	VM	1	1	25	4	13.2	0.8	###	2000
JTMA8724	TDFN3x3-10	Buck	COT	1	1	25	4.5	25	0.6	###	80
JTMA8725/A	SOP-8P	Buck	VM	1	1	25	4.5	13.2	0.8	###	16000
JTMA8726	TQFN3x3-10	Buck	VM	1	1	25	4.5	13.2	0.6	###	2500
JTMA8727/L	TDFN3x3-10	Buck	COT	1	1	30	3	25	0.8	###	2000
JTMA8728	TQFN3x3-16	Buck	COT	1	1	30	1.8	28	0.6	5	600
JTMA8732	QFN4x4-24	Buck	VM	2	1	50	4.5	13.2	0.6	###	5000
JTMA8811	TQFN4x4-24	Buck	COT	1	2	15	6	25	2	N	550
JTMA8812	TQFN4x4-24	Buck	COT	1	2	15	6	25	2	N	550
JTMA8813/A	TQFN4x4-24	Buck	COT	1	2	20	3	28	0.75	5	800
JTMA8813/A	TQFN3x3-20	Buck	COT	1	2	20	3	28	0.75	5	800
JTMA8814	TQFN3x3-16	Buck	COT	1	1	20	1.8	28	0.75	5	400
JTMA8815	QFN3.5x3.5-14	Buck	COT	1	1	20	1.8	28	0.75	5	400
JTMA8815	TQFN3x3-16	Buck	COT	1	1	20	1.8	28	0.75	5	400
JTMA8816	TQFN3x3-16	Buck	COT	1	2	20	1.8	28	0.75	5	400
JTMA8819	QFN3x3-20	Buck	COT	1	2	20	3	28	1.8 /1.5 /0.5	5	740
JTMA8819	TQFN3x3-16	Buck	COT	1	2	20	3	28	1.8 /1.5 /0.5	5	740
JTMA8820	TQFN4x4-24	Buck	CM	1	2	15	5	28	0.5	N	3000
JTMA8820	QFN3x3-20	Buck	CM	1	2	15	5	28	0.5	N	3000
JTMA8821	TDFN3x3-10	Buck	COT	1	1	20	1.8	28	0.5	5	250
JTMA8822/C	TQFN3x3-20	Buck	COT	1	2	15	6	25	2	N	550
JTMA8823A/B	TQFN3x3-20	Buck	COT	1	2	15	5.5	25	0.6	N	50
JTMA8868	TQFN3x3-20	Buck	COT	1	2	20	3	28	0.75	5	180
JTMA7088	QFN4x4-24	Multiphase	VM	2	1	60	3.1	13.2	0.85	12	5000
JTMA7165A/B/C	SOP-8P	Buck	VM	1	1	20	2.9	13.2	0.8	12	16000
JTMA7159A	SOP-20	Buck	VM	2	2	30	10	13.2	1	12	5000
JTMA8828	TDFN3x3-10	Buck	COT	1	1	25	1.8	28	0.7	5	250
JTMA8728	TQFN 3x3 16	Buck	COT	1	1	30	1.8	28	0.6	5	600

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