The JTMA8700, two-phase PWM control IC, provides a precision(2)

产品封装图 (Package)

六.电路原理图

七,功能概述
Offset Current Adjust
The JTMA8700 integrated IOFS allows the offset current to adjust phase current. The IOFS pin voltage is nominal
0.5V when connecting a resistor to GND and 1.5V when connecting a resistor to VREF. Connecting a resistor from
IOFS pin to GND generate a current source as:IOFS= 0.5V/RIOFS
This current is add to phase 1 current signal ISEN1 for cur-rent balance. Consequently, phase 2 will share more
percentage of output current. Connecting a resistor from
IOFS pin to VREF generates a current source as:
IOFS= (2V-1.5V) /RIOFS
This current is add to phase 2 current signal ISEN2 for cur-rent balance. Consequently, phase 1 will share more
percentage of output current.

Over-Temperature Protection (OTP)
The over-temperature circuit limits the junction tempera-ture of the JTMA8700. When the junction temperature exo
ceeds 150 C, a thermal sensor pulls UGTAEx and LGATEx low, allowing the devices to cool. The thermal sensor
allows the converters to start a soft-start process and regulates the output voltage again after the junction temo perature cools by 20 C. The OTP is designed with a 20 C hysteresis to lower the average Junction Temperature
(TJ) during continuous thermal overload conditions increasing the lifetime of the device.

OVP
The over-voltage protection (OVP) circuit monitors the FB (VFB) voltage to prevent the output from over-voltage. When
the V FB rises to 130% of the EAP voltage (V EAP), the JTMA 8700 turns off high-side and turn on low-side
MOSFETs to sink output voltage (VOUT). As soon as the VFB falls below 110% of V EAP, the OVP comparator is
disengaged. The chip will restore its normal operation.
UVP
The under-voltage protection circuit monitors the voltage on FB (VFB) by Under-Voltage (UV) comparator to protect
the PWM converter against short-circuit conditions. When the VFB falls below the falling UVP threshold (50% VEAP), a
fault signal is generated and the device turns off highside and low-side MOSFETs. The converter shuts down
and the output is latched to be floating. The JTMA8700 will initials a soft-start process until re-cycle RT/EN or VCC

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	5月12日	2100
JTMA7120A	SOP-8	Buck	VM	1	1	20	2.2	13.2	0.8	5月12日	2100
JTMA7037/A/B	SOP-8	Buck	VM	1	1	5	5	13.2	1.25 / 0.8	5月12日	3000
JTMA7037/A/B	TSSOP-8	Buck	VM	1	1	5	5	13.2	1.25 / 0.8	5月12日	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	5月12日	4000
JTMA7066	QFN5x5-32	Buck	VM	1	2	20	5	13.2	0.6	5月12日	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	5月12日	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	5月12日	4000
JTMA7181	SOP-8		VM	1	2	-	-	-	-	5月12日	550
JTMA7181	DFN3x3-10		VM	1	2	-	-	-	-	5月12日	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	5月12日	4000
JTMA8720B	SOP8-P	Buck	VM	1	1	20	3	13.2	0.8	5月12日	2500
JTMA8720B	TDFN3x3-10	Buck	VM	1	1	20	3	13.2	0.8	5月12日	2500
JTMA8722A/B/C/D	SOP8-P	Buck	VM	1	1	25	3	13.2	0.6 /0.8	5月12日	1200
JTMA8723	TDFN3x3-10	Buck	VM	1	1	25	4	13.2	0.8	5月12日	2000
JTMA8724	TDFN3x3-10	Buck	COT	1	1	25	4.5	25	0.6	5月12日	80
JTMA8725/A	SOP-8P	Buck	VM	1	1	25	4.5	13.2	0.8	5月12日	16000
JTMA8726	TQFN3x3-10	Buck	VM	1	1	25	4.5	13.2	0.6	5月12日	2500
JTMA8727/L	TDFN3x3-10	Buck	COT	1	1	30	3	25	0.8	5月12日	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	5月12日	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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